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Evening Chabura / Gemara / Halacha / Rabbi Baruch Bodenheim's shiurim / Shabbos / Shabbos

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Rabbi Baruch Bodenheim: Gemara Shabbos: Borer – Monday night shiur, Teves 3 (12/22/25)

Borer on the same item

Is it permitted to select and separate the large pieces from the smaller pieces of the same item?

We discussed the ruling of the תרומות הדשן and the שולחן ערוך אורח חיים ס’ שי”ט סע’ ג that it is permitted 

https://www.hebrewbooks.org/pdfpager.aspx?req=40527&st=&pgnum=263&hilite=

We discussed the ט”ז ס”ק ב who brings multiple proofs that there is Borer by one time of food item. 

The משנה ברורה ס”ק טו rules like the Shulchan Aruch 

Learn משנה שבת דף קלט: “ונותנין ביצה מסננת של חרדל

Why is it permitted to separate the yolk from the egg white?

Learn רש”י and the ר”ן

There are three explanations

Learn טור ס’ שי”ט סע’ טו

Learn ב”ח ס”ק י  

Learn מגן אברהם ס’ שי”ט ס”ק טז

Learn ט”ז ס’ שי”ט ס”ק יב

Learn שולחן ערוך אורח חיים ס’ שי”ט סע’ טו and משנה ברורה 

See אורחת שבת חלק א פרק כ סע’ לב-לז

And קובץ הלכות חלק ב פרק כזה סע’ י”ח – מח 

Gemara / Rabbi Baruch Bodenheim's shiurim / Shabbos

 by 

Rabbi Baruch Bodenheim: Gemara Shabbos: Perek Kirah, יום שני, Zos Chanukah – Cooking After Cooking (12/22/25)

Cooking After Cooking 

Quickly review the…גמרא דף לט. “כל שבא (until the two dots) which clearly states that once an item was cooked it may be reheated inside a Kli Rishon.

https://hebrewbooks.org/shas.aspx?mesechta=2&daf=39&format=pdf

Does this apply to liquid that was cooked and cooled down?

Learn גמרא דף לד. “ואמר אבא מפני מה (three lines from bottom of the Amud) until “אמר ליה 

https://hebrewbooks.org/shas.aspx?mesechta=2&daf=34&format=pdf

Learn רש'”י דף לד. “גזירה שמא (three lines from bottom of the page) 

And רא”ש פרק ג ס’ י “ולמאי דפ’ דלא שייך בישול (last few lines) and continue learning ס’ יא

https://hebrewbooks.org/pdfpager.aspx?req=37953&st=&pgnum=354

Learn ר”ן פרק ג. דף מג. “תנו רבנו מביא אדם קיתון של מים

https://hebrewbooks.org/pdfpager.aspx?req=37953&st=&pgnum=587

Learn טור ס’ שי”ח סע’ ד & טו

https://hebrewbooks.org/pdfpager.aspx?req=14268&st=&pgnum=40

https://hebrewbooks.org/pdfpager.aspx?req=14268&st=&pgnum=41

https://hebrewbooks.org/pdfpager.aspx?req=14268&st=&pgnum=47

Learn בית יוסף & ב”ח 

How does the Mechaber rule?

How does the Rema rule? 

Learn שולחן ערוך אורח חיים ס’ שי”ח סע’ ד & טו

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=273

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=280

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=281

Learn משנה ברורה 

Evening Chabura / Gemara / Halacha / Rabbi Baruch Bodenheim's shiurim / Shabbos / Shabbos

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Rabbi Baruch Bodenheim: Gemara Shabbos: Borer – Wednesday night shiur, Chanukah 4th night – Chanukah Sugya (12/17/25)

Chanukah Sugya:

Muktza status of oil and wicks from the Menorah 

Learn גמרא שבת דף כא: “וכתב אין זקוק לה ורמינהו (twelfth line from top of the Amud) until the two dots.

https://hebrewbooks.org/shas.aspx?mesechta=2&daf=21b&format=pdf

What does the לשיעורה mean?

See Rashi

Learn רי”ף for a different explanation.

https://hebrewbooks.org/pdfpager.aspx?req=37953&st=&pgnum=567&hilite=

Is it permitted to use the leftover oil of the candle went out in middle of the first half an hour?

Learn ר”ן who explains based on the Rif it is permitted. And brings the position of the גאונים who say one is prohibited from using the leftover oil even after chanukah 

Learn תוס’ שבת דף מד. שבנר 

https://hebrewbooks.org/shas.aspx?mesechta=2&daf=44&format=pdf

According to Tosfos is the oil that remains even after the candle lit for half an hour prohibited to be used?

Why is the remaining oil different than the leftover of other Mitzvos which are permitted to be used after the Yom tov – for example the wood used for ones Sukkah?

See Tosfos answer

Learn תוס’ רא”ש דף מד 

How do we rule?

Learn רא”ש פרק ה’ ס’ ג & ס’ ט

https://hebrewbooks.org/pdfpager.aspx?req=37953&st=&pgnum=345&hilite=

Learn טור ס’ תרע”ב   

Learn טור ס’ תרע”ז סע’ ד

https://hebrewbooks.org/pdfpager.aspx?req=14268&st=&pgnum=606

Major Question:

The Tur seems to contradict himself in regards to using leftover oil?

Learn בית יוסף ס’ תרע”ז ס”ק ד and ב”ח ס”ק ה who give two answers how to resolve the contradictory ruling of the Tur.

What is the difference between the two answers of the Beis Yosef?

How do we conclude lhalacha?

Learn שולחן ערוך אורח חיים ס’ תרע”ז סע’ ד 

https://hebrewbooks.org/pdfpager.aspx?req=14327&st=&pgnum=421

https://hebrewbooks.org/pdfpager.aspx?req=14327&st=&pgnum=422

Learn מגן אברהם ס”ק י

Learn משנה ברורה and ביאור הלכה 

https://hebrewbooks.org/pdfpager.aspx?req=60391&st=&pgnum=297

Learn שולחן ערוך אורח חיים ס’ תרע”ב סע’ ב and משנה ברורה ס”ק ז

https://hebrewbooks.org/pdfpager.aspx?req=60391&st=&pgnum=285

See משנה ברורה ס”ק ח for a new reason from the מהרש”ל not to use the light from the Menorah after it burnt for the required amount of time. 

Chanukah / Gemara / Rabbi Baruch Bodenheim's shiurim / Shabbos

 by 

Rabbi Baruch Bodenheim: Gemara Shabbos: Perek Kirah, יום רביעי, Chanukah Day 3, Chanukah Sugya (12/17/25)

Chanukah Sugya:

Muktza status of oil and wicks from the Menorah 

Review גמרא שבת דף כא: “וכתב אין זקוק לה ורמינהו (twelfth line from top of the Amud) until the two dots.

https://hebrewbooks.org/shas.aspx?mesechta=2&daf=21b&format=pdf

What does the לשיעורה mean?

See Rashi

Learn רי”ף for a different explanation.

https://hebrewbooks.org/pdfpager.aspx?req=37953&st=&pgnum=567&hilite=

Is it permitted to use the leftover oil of the candle went out in middle of the first half an hour?

Learn ר”ן who explains based on the Rif it is permitted. And brings the position of the גאונים who say one is prohibited from using the leftover oil even after chanukah 

Learn תוס’ שבת דף מד. שבנר 

https://hebrewbooks.org/shas.aspx?mesechta=2&daf=44&format=pdf

According to Tosfos is the oil that remains even after the candle lit for half an hour prohibited to be used?

Why is the remaining oil different than the leftover of other Mitzvos which are permitted to be used after the Yom tov – for example the wood used for ones Sukkah?

See Tosfos answer

Learn תוס’ רא”ש דף מד 

How do we rule?

Learn רא”ש פרק ה’ ס’ ט

https://hebrewbooks.org/pdfpager.aspx?req=37953&st=&pgnum=345&hilite=

Learn טור ס’ תרע”ב   

Learn טור ס’ תרע”ז סע’ ד

https://hebrewbooks.org/pdfpager.aspx?req=14268&st=&pgnum=606

Major Question:

The Tur seems to contradict himself in regards to using leftover oil?

Learn בית יוסף ס’ תרע”ז ס”ק ד & ב”ח ס”ק ה who resolve the contradictory ruling of the Tur.

How do we conclude lhalacha?

Learn שולחן ערוך אורח חיים ס’ תרע”ז סע’ ד 

https://hebrewbooks.org/pdfpager.aspx?req=14327&st=&pgnum=421

https://hebrewbooks.org/pdfpager.aspx?req=14327&st=&pgnum=422

Learn מגן אברהם ס”ק י

Learn משנה ברורה and ביאור הלכה 

https://hebrewbooks.org/pdfpager.aspx?req=60391&st=&pgnum=297

Learn שולחן ערוך אורח חיים ס’ תרע”ב סע’ ב and משנה ברורה ס”ק ז

https://hebrewbooks.org/pdfpager.aspx?req=60391&st=&pgnum=285

Chanukah / Gemara / Rabbi Baruch Bodenheim's shiurim / Shabbos

 by 

Rabbi Baruch Bodenheim: Gemara Shabbos: Perek Kirah, יום שלישי, Chanukah Day 2, Chanukah Sugya (12/16/25)

Chanukah Sugya:

Muktza status of oil and wicks from the Menorah 

Review גמרא שבת דף כא: “וכתב אין זקוק לה ורמינהו (twelfth line from top of the Amud) until the two dots.

https://hebrewbooks.org/shas.aspx?mesechta=2&daf=21b&format=pdf

What does the לשיעורה mean?

See Rashi

Learn רי”ף for a different explanation.

https://hebrewbooks.org/pdfpager.aspx?req=37953&st=&pgnum=567&hilite=

Is it permitted to use the leftover oil of the candle went out in middle of the first half an hour?

Learn ר”ן who explains based on the Rif it is permitted. And brings the position of the גאונים who say one is prohibited from using the leftover oil even after chanukah 

Learn תוס’ שבת דף מד. שבנר 

https://hebrewbooks.org/shas.aspx?mesechta=2&daf=44&format=pdf

According to Tosfos is the oil that remains even after the candle lit for half an hour prohibited to be used?

Why is the remaining oil different than the leftover of other Mitzvos which are permitted to be used after the Yom tov – for example the wood used for ones Sukkah?

See Tosfos answer

Learn תוס’ רא”ש דף מד 

How do we rule?

Learn רא”ש פרק ה’ ס’ ט

https://hebrewbooks.org/pdfpager.aspx?req=37953&st=&pgnum=345&hilite=

Learn טור ס’ תרע”ב   

Learn טור ס’ תרע”ז סע’ ד

https://hebrewbooks.org/pdfpager.aspx?req=14268&st=&pgnum=606

Major Question:

The Tur seems to contradict himself in regards to using leftover oil?

Learn בית יוסף ס’ תרע”ז ס”ק ד & ב”ח ס”ק ה who resolve the contradictory ruling of the Tur.

How do we conclude lhalacha?

Learn שולחן ערוך אורח חיים ס’ תרע”ז סע’ ד 

https://hebrewbooks.org/pdfpager.aspx?req=14327&st=&pgnum=421

https://hebrewbooks.org/pdfpager.aspx?req=14327&st=&pgnum=422

Learn מגן אברהם ס”ק י

Learn משנה ברורה and ביאור הלכה 

https://hebrewbooks.org/pdfpager.aspx?req=60391&st=&pgnum=297

Learn שולחן ערוך אורח חיים ס’ תרע”ב סע’ ב and משנה ברורה ס”ק ז

https://hebrewbooks.org/pdfpager.aspx?req=60391&st=&pgnum=285

Chanukah / Gemara / Rabbi Baruch Bodenheim's shiurim / Shabbos

 by 

Rabbi Baruch Bodenheim: Gemara Shabbos: Perek Kirah, יום שני, First day of Chanukah, Chanukah Sugya Daf 45a (12/15/25)

Chanukah Sugya:

Muktza status of oil and wicks from the Menorah 

Learn גמרא שבת דף כא: “וכתב אין זקוק לה ורמינהו (twelfth line from top of the Amud) until the two dots.

What does the לשיעורה mean?

See Rashi

Learn רי”ף for a different explanation.

Is it permitted to use the leftover oil of the candle went out in middle of the first half an hour?

Learn ר”ן

Learn תוס’ שבת דף מד. שבנר who argues on the ר”ן

According to Tosfos is the oil that remains even after the candle lit for half an hour prohibited to be used?

Why is the remaining oil different than the leftover of other Mitzvos which are permitted to be used after the Yom tov – for example the wood used for ones Sukkah?

See Tosfos answer

Learn תוס’ רא”ש דף מד 

How do we rule lhalacha?

Learn רא”ש פרק ה’ ס’ ט

Learn טור ס’ תרע”ז סע’ ד

Learn בית יוסף  who questions the ruling of the Tur

Learn שולחן ערוך אורח חיים ס’ תרע”ז סע’ ד 

Learn מגן אברהם ס”ק י

Learn משנה ברורה  and ביאור הלכה 

Learn שולחן ערוך אורח חיים ס’ תרע”ב סע’ ב and משנה ברורה ס”ק ז

Gemara / Rabbi Baruch Bodenheim's shiurim / Shabbos

 by 

Rabbi Baruch Bodenheim: Gemara Shabbos: Perek Kirah, יום חמישי, Kislev 21, Daf 42b – Sugya – Solid hot foods & Ladles (12/11/25)

Ladle  

When using a ladle to spoon out from a Kli Rishon; is the bowl that the soup is being poured into considered a Kli Sheini or a Kli Shlishi?

See ט”ז אורח חיים ס’ שי”ח ס”ק י”ט

https://hebrewbooks.org/pdfpager.aspx?req=14325&st=&pgnum=158

Learn משנה ברורה ס’ שי”ח ס”ק פז who brings that it is considered a Kli Rishon.

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=280&hilite=

However see the leniency the Mishna Berura ס”ק מה says regarding dipping challah inside the bowl of soup.

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=276&hilite=

See קובץ הלכות הלכות שבת פרק כה סע’ י 

Solid hot food

Learn מגן אברהם ס’ שי”ח ס”ק מ”ה

https://hebrewbooks.org/pdfpager.aspx?req=14325&st=&pgnum=159

See ש”ך יורה דעה ס’ קה ס”ק ח 

https://hebrewbooks.org/pdfpager.aspx?req=9145&st=&pgnum=497

https://hebrewbooks.org/pdfpager.aspx?req=9145&st=&pgnum=498

Who says that a solid hot food item does not receive the leniency when placed in a Kli Sheini or Shlishi. See the reason why?

Learn משנה ברורה ס’ שי”ח ס”ק מה “in middle ”דיש פוסקים שסוברים ….

Based on the above may one place a pickle on top of a hot piece of kugel?

See אורחת שבת חלק א פרק א סע’ סא & הערה קמו- קמז

Thermos & Styrofoam cup

Does hot water poured from a Kil Rishon into a thermos have the status of a Kli Sheini as the thermos was not the utensil the water was cooked inside of or does it have the status of a Kli Rishon as the thermos retains the heat unlike a regular Kli Sheini?

See שמירת שבת כהלכתו פרק א הערה קכב

See קובץ הלכות הלכות שבת פרק כה סע’ ט 

Cooking after cooking 

Quickly review the משנה דף לח עמוד ב which clearly says that once an item was cooked it may be reheated inside a Kli Rishon. 

Does this apply to liquid that was cooked and cooled down?

Learn רש'”י דף לד. “משחשכה 

And רא”ש פרק כ ס’ יא

Learn שולחן ערוך אורח חיים ס’ שי”ח סע’ ד & טו

How does the Mechaber rule?

How does the Rema rule? 

Learn משנה ברורה 

Evening Chabura / Gemara / Halacha / Rabbi Baruch Bodenheim's shiurim / Shabbos / Shabbos

 by 

Rabbi Baruch Bodenheim: Gemara Shabbos: Borer – Monday & Wednesday night shiur, Kislev 21 – Daf 74a – One item (12/10/25)

Borer on the same item

Is it permitted to select and separate the large pieces from the smaller pieces of the same item?

We discussed the ruling of the תרומות הדשן and the שולחן ערוך אורח חיים ס’ שי”ט סע’ ג that it is permitted 

https://www.hebrewbooks.org/pdfpager.aspx?req=40527&st=&pgnum=263&hilite=

We discussed the ט”ז ס”ק ב who brings multiple proofs that there is Borer by one time of food item. 

The משנה ברורה ס”ק טו rules like the Shulchan Aruch 

Learn משנה שבת דף קלט: “ונותנין ביצה מסננת של חרדל

Why is it permitted to separate the yolk from the egg white?

Learn רש”י and the ר”ן

There are three explanations

Learn טור ס’ שי”ט סע’ טו

Learn ב”ח ס”ק י  

Learn מגן אברהם ס’ שי”ט ס”ק טז

Learn ט”ז ס’ שי”ט ס”ק יב

Learn שולחן ערוך אורח חיים ס’ שי”ט סע’ טו and משנה ברורה 

See אורחת שבת חלק א פרק כ סע’ לב-לז

And קובץ הלכות חלק ב פרק כזה סע’ י”ח – מח 

Gemara / Rabbi Baruch Bodenheim's shiurim / Shabbos

 by 

Rabbi Baruch Bodenheim: Gemara Shabbos: Perek Kirah, יום רביעי, Kislev 20, Yahrzeit of Rebbetzin Singer a”h, Daf 42b – Sugya – Solid hot foods & Ladles (12/10/25)

Making tea on Shabbos 

Based on the halachos of Kli Sheini & Kli Shlishi 

What is the best permissible method to make hot tea on Shabbos?

See משנה ברורה ס”ק לט for a lengthy discussion about this. 

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=275

Ladle 

When using a ladle to spoon out from a Kli Rishon; is the bowl that the soup is being poured into considered a Kli Sheini or a Kli Shlishi?

See ט”ז אורח חיים ס’ שי”ח ס”ק י”ט

Learn משנה ברורה ס’ שי”ח ס”ק מה who brings that it is considered a Kli Rishon. 

However see the leniency the Mishna Berura says regarding dipping challah inside the bowl of soup. 

See קובץ הלכות הלכות שבת פרק כה סע’ י 

Solid hot food

Learn מגן אברהם ס’ שי”ח ס”ק מ”ה

See ש”ך יורה דעה ס’ קה ס”ק ח 

Who says that a solid hot food item does not receive the leniency when placed in a Kli Sheini or Shlishi. See the reason why?

Learn משנה ברורה ס’ שי”ח ס”ק מה “in middle ”דיש פוסקים שסוברים ….

Based on the above may one place a pickle on top of a hot piece of kugel?

See אורחת שבת חלק א פרק א סע’ סא & הערה קמו- קמז

Thermos & Styrofoam cup

Does hot water poured from a Kil Rishon into a thermos have the status of a Kli Sheini as the thermos was not the utensil the water was cooked inside of or does it have the status of a Kli Rishon as the thermos retains the heat unlike a regular Kli Sheini?

See שמירת שבת כהלכתו פרק א הערה קכב

See קובץ הלכות הלכות שבת פרק כה סע’ ט 

Cooking after cooking

Quickly review the משנה דף לח עמוד ב which clearly says that once an item was cooked it may be reheated inside a Kli Rishon. 

Does this apply to liquid that was cooked and cooled down?

Learn רש'”י דף לד. “משחשכה 

And רא”ש פרק כ ס’ יא

Learn שולחן ערוך אורח חיים ס’ שי”ח סע’ ד & טו

How does the Mechaber rule?

How does the Rema rule? 

Learn משנה ברורה 

Gemara / Rabbi Baruch Bodenheim's shiurim / Shabbos

 by 

Rabbi Baruch Bodenheim: Gemara Shabbos: Perek Kirah, יום שלישי, Kislev 19 – Daf 42b Sugya – Kli Shlishi (12/09/25)

Is there a difference in regards to the heat of a Kli Sheini to affect cooking?

Learn רמב”ם ה’ מעשרות פרק כ הלכה יד  

https://hebrewbooks.org/pdfpager.aspx?req=58962&st=&pgnum=129

Learn חיי אדם ה’ שבת פרק כ סע’ ד and the  שער מצות הארץ בינת אדם פרק כ אות א  (on bottom) who introduces a new reason to prohibit 

https://hebrewbooks.org/pdfpager.aspx?req=49397&st=&pgnum=257&hilite=

What are the sources of the Chayei Adam for this new chidush?

Learn רמב”ם ה’ שבת פרק כב הלכה ו  

https://hebrewbooks.org/pdfpager.aspx?req=14278&st=&pgnum=100

Do we rule in accordance with this stringency?

By a Kli Sheini?

By a Kli Shlishi?

Learn משנה ברורה ס”ק מ”ח

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=276

And חזון איש אורח חיים ס’ נב אות י”ט 

https://hebrewbooks.org/pdfpager.aspx?req=14336&st=&pgnum=161

Based on the halachos of Kli Sheini & Kli Shlishi 

What is the best permissible method to make hot tea on Shabbos?

See משנה ברורה ס”ק לט for a lengthy discussion about this. 

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=275

The ladle argument 

When using a ladle to spoon out from a Kli Rishon; is the bowl that the soup is being poured into considered a Kli Sheini or a Kli Shlishi?

Learn משנה ברורה ס’ שי”ח ס”ק פז

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=280

Solid hot food

Learn 

Who says that a solid hot food item does not receive the leniency when placed in a Kli Sheini or Shlishi. See the reason why?

Learn משנה ברורה ס’ שי”ח ס”ק מה “in middle ”דיש פוסקים שוברים …

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=276&hilite=

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Evening Chabura / Gemara / Halacha / Rabbi Baruch Bodenheim's shiurim / Shabbos / Shabbos

 by 

Rabbi Baruch Bodenheim: Gemara Shabbos: Borer – Monday – Kislev 19 – Daf 74a – One item (12/08/25)

Borer on the same item

Is it permitted to select and separate the large pieces from the smaller pieces of the same item?

Do we rule like the תרומות הדשן ?

https://www.hebrewbooks.org/pdfpager.aspx?req=1835&pgnum=28

Learn שולחן ערוך אורח חיים ס’ שי”ט סע’ ג

https://www.hebrewbooks.org/pdfpager.aspx?req=40527&st=&pgnum=263&hilite=

Learn ט”ז ס”ק ב who brings multiple proofs that there is Borer by one time of food item. 

Clarify all the proofs of the Taz

https://www.hebrewbooks.org/pdfpager.aspx?req=14211&st=&pgnum=157&hilite=

Do we rule like the Taz?

Learn משנה ברורה 

Are the following items considered one species of two species?

Grilled and boiled food items 

Chicken breast and a chicken legs  

Different types of apples 

Whole matza and broken pieces 

White part of an egg and the yolk

See אורחת שבת חלק א פרק כ סע’ לב-לז

And קובץ הלכות חלק ב פרק כזה סע’ י”ח – מח 

Gemara / Rabbi Baruch Bodenheim's shiurim / Shabbos

 by 

Rabbi Baruch Bodenheim: Gemara Shabbos: Perek Kirah, יום שני, Kislev 18 – Daf 42b Sugya – Kli Shlishi (12/08/25)

Kli Shlishi

The Gemara clearly states that there are items that are קלי בישול and cook easily and quickly. Those items can cook inside a Kli Sheini. 

The Magen Avraham ruled that since we don’t know what items are not קלי בישול we have to be strict on placing any raw items that is raw except for the items listed in the Gemara that definitely do not cook in a Kli Sheini. 

Point to Consider 

Do we have the concept of קלי בישול in regards to a Kli Shlishi?

Summarize the opinions we learn regarding if there is difference between a Kli Sheini and a Kli Shlishi.

1. The dispute between the Beis Yosef and the Bach.

https://hebrewbooks.org/pdfpager.aspx?req=14268&st=&pgnum=45

2. The position of the Pri Megadim and his proof 

https://hebrewbooks.org/pdfpager.aspx?req=41248&st=&pgnum=204

3. The dispute between the Mishna Berura and the Chazon Ish

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=276

https://hebrewbooks.org/pdfpager.aspx?req=14336&st=&pgnum=161

4. The ruling of Rav Moshe Feinstein zt”l and the basis of his ruling 

See אגרות משה אורח חיים חלק ד ס’ עד בישול אות טו & יח 

https://hebrewbooks.org/pdfpager.aspx?req=920&st=&pgnum=139

https://hebrewbooks.org/pdfpager.aspx?req=920&st=&pgnum=140

Is there a difference in regards to the heat of a Kli Sheini to affect cooking?

Learn חיי אדם ה’ שבת פרק כ סע’ ד and the נשמת אדם (on bottom) who introduces a new reason to prohibit 

https://hebrewbooks.org/pdfpager.aspx?req=49397&st=&pgnum=257&hilite=

What are the sources of the Chayei Adam for this new concept?

Do we rule in accordance with this stringency?

Learn משנה ברורה ס”ק מ”ח

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=276

And חזון איש אורח חיים ס’ נב אות י”ט 

https://hebrewbooks.org/pdfpager.aspx?req=14336&st=&pgnum=161

What is the best permissible method to make hot tea on Shabbos?

See משנה ברורה ס”ק לט for a lengthy discussion about this. 

https://hebrewbooks.org/pdfpager.aspx?req=60388&st=&pgnum=275