Hatmana (definition: insulating a pot of hot food) may not be done on Shabbos even with a substance that does not increase heat. However, during the time-frame that is questionable if it’s night (Bein Hashemashos), Hatmana may be done. Hatmana may not be done in a substance that adds heat, even while it is yet day (before Shabbos). If one did Hatmana in a substance that adds heat, the food is forbidden even after the fact. But this specifically refers only to cold food heated (by Hatmana) or (cooked food) improved by further cooking, but if it only retained its original warmth, it is permitted (to eat the food). RAMA: There are those who say that if one forgot and did Hatmana accidentally with a substance that adds heat, it is permissible to eat. [Ha'gahos Mordechai]. And there are those who say, that all this is only forbidden when it is done for the night (meal), but if the Hatmana is done [on Friday] for the following day, while it is still day, it is permissible to do Hatmana in a substance which adds heat. [Mordechai, beginning of the chapter 'Kira'; Beis Yosef, end of Siman 253 in the name of Shbolei Leket]. After the fact one can rely on this opinion provided one does not become accustomed to doing so.

Hatmana (definition: insulating a pot of hot food) may not be done on Shabbos even with a substance that does not increase heat. However, during the time-frame that is questionable if it’s night (Bein Hashemashos), Hatmana may be done. Hatmana may not be done in a substance that adds heat, even while it is yet day (before Shabbos). If one did Hatmana in a substance that adds heat, the food is forbidden even after the fact. But this specifically refers only to cold food heated (by Hatmana) or (cooked food) improved by further cooking, but if it only retained its original warmth, it is permitted (to eat the food). RAMA: There are those who say that if one forgot and did Hatmana accidentally with a substance that adds heat, it is permissible to eat. [Ha'gahos Mordechai]. And there are those who say, that all this is only forbidden when it is done for the night (meal), but if the Hatmana is done [on Friday] for the following day, while it is still day, it is permissible to do Hatmana in a substance which adds heat. [Mordechai, beginning of the chapter 'Kira'; Beis Yosef, end of Siman 253 in the name of Shbolei Leket]. After the fact one can rely on this opinion provided one does not become accustomed to doing so.

The Laws Governing the Preparation of Fire before the Onset of Shabbos, 3 Seifim: It is forbidden to make a large fire – a medurah – using wood as fuel close to nightfall [on Friday] unless the fire catches hold to the extent that the flame burns on its own accord without the assistance of other wood (I.e., flaming wood from an outside source.) If [only] one log is [burning], the fire must take hold of the majority of its circumference and its width. If it is not kindled as such (like above) it is forbidden to make use of it on Shabbat. This is a decree, lest one stir [the wood] on Shabbos, moving [the pieces of] wood until the flame ascends on its own accord. If, however, [the wood] was kindled to the extent described [in the previous subsection] while it was still day, a person may warm himself by [that fire] and use its light, regardless of whether [the wood] was [burning] on the ground or on a holder for fire. And even substances that are forbidden to be used as wicks for [the Shabbos] lights.

Elevator on Shabbas in Halacha

Chazara, On Shabbos, it is permissible to place onto a pot of hot water, a dish of food that is already fully cooked such as Panades or the like, in order to warm it, since he is not cooking in a usual manner. However it is definitely forbidden to place (food) under cloths that cover a water kettle. RAMA: similarly it is forbidden to place (food) on a Kirah even if it is Gerufa and Ketuma, as the sages only permitted Chazora (but not placing a pot for the first time), as has been explained above. Some (authorities) permit placing (a pot of food) into a Tanur used for baking on Erev Shabbos, when no food was left warming in it (it was merely used for baking on Erev Shabbos), only a small amount of heat remains and there need be no concern that this will cause it (the pot) to be cooked – provided (the food) has not cooled completely. Some, however, are stringent here, and (hold that) if the heat of the Tanur is so intense that it is of Yad soledes bo, it is forbidden. See below Siman 318. One may not tell a non-Jew to do anything that is forbidden to do himself. It is therefore forbidden to tell a non-Jew to heat up the pot (of food) that has cooled. If one does so, it is forbidden to eat it even cold. [Beis Yosef and the Teshuvos HaRashba] However, if the food has not cooled below the temperature at which it is edible, it may be eaten if the non-Jew heats it up. For this reason it is common practice to have non-Jews remove pots of food from ovens in which they have been stored to retain their heat, and place them next to or on top of a heating stove, and then have the (non-Jewish) maidservant light the stove, whereupon the food will become boiling hot once again. However it is forbidden to do this through a Jew. (Terumas HaDeshen) If, however, the pots are still hot they may be placed next to the heating stove. The reason is that, as has been explained, our ovens have a status of a Kirah, and placing it next to a Kirah, which is not Garuf Ve’katum, has the same law as placing directly on top of it when it is Garuf Ve’katum (which is permitted). It has already been stated that the customary practice is to be lenient (and permit) to do Chazora [returning a pot to the stove] even if the pot has been placed on the ground. Similarly, placing (a pot) next to an oven, which is not Garuf Ve’katum (is permitted) if the food is still hot and fully cooked. It is a widespread, accepted practice to permit this. See below Siman 318.

Chazara, On Shabbos, it is permissible to place onto a pot of hot water, a dish of food that is already fully cooked such as Panades or the like, in order to warm it, since he is not cooking in a usual manner. However it is definitely forbidden to place (food) under cloths that cover a water kettle. RAMA: similarly it is forbidden to place (food) on a Kirah even if it is Gerufa and Ketuma, as the sages only permitted Chazora (but not placing a pot for the first time), as has been explained above. Some (authorities) permit placing (a pot of food) into a Tanur used for baking on Erev Shabbos, when no food was left warming in it (it was merely used for baking on Erev Shabbos), only a small amount of heat remains and there need be no concern that this will cause it (the pot) to be cooked – provided (the food) has not cooled completely. Some, however, are stringent here, and (hold that) if the heat of the Tanur is so intense that it is of Yad soledes bo, it is forbidden. See below Siman 318. One may not tell a non-Jew to do anything that is forbidden to do himself. It is therefore forbidden to tell a non-Jew to heat up the pot (of food) that has cooled. If one does so, it is forbidden to eat it even cold. [Beis Yosef and the Teshuvos HaRashba] However, if the food has not cooled below the temperature at which it is edible, it may be eaten if the non-Jew heats it up. For this reason it is common practice to have non-Jews remove pots of food from ovens in which they have been stored to retain their heat, and place them next to or on top of a heating stove, and then have the (non-Jewish) maidservant light the stove, whereupon the food will become boiling hot once again. However it is forbidden to do this through a Jew. (Terumas HaDeshen) If, however, the pots are still hot they may be placed next to the heating stove. The reason is that, as has been explained, our ovens have a status of a Kirah, and placing it next to a Kirah, which is not Garuf Ve’katum, has the same law as placing directly on top of it when it is Garuf Ve’katum (which is permitted). It has already been stated that the customary practice is to be lenient (and permit) to do Chazora [returning a pot to the stove] even if the pot has been placed on the ground. Similarly, placing (a pot) next to an oven, which is not Garuf Ve’katum (is permitted) if the food is still hot and fully cooked. It is a widespread, accepted practice to permit this. See below Siman 318.

Chazara, Shiyah: The halachos of returning food to the fire on shabbos. - If one rises early (on Shabbos morning) and finds that the food in his pot is beginning to burn, if he is concerned that it might burn more, he may remove it, place a used empty pot on the mouth of the Kirah, and then put the pot containing the food atop the empty pot. One should be careful not to place the pot (containing the food) on the ground and it should be boiling hot. (It has already been stated that it is customary to be lenient (and permit returning a pot to a stove) even where it has been placed on the ground).

Chazara: The halachos of returning food to the fire on shabbos: -- A Kirah that is Gerufa or Ketuma, if one removes a pot from it even on Shabbos, he may return it as long as it is boiling hot RAMA: and it is still in his hand (Tur) and he has not placed it on the floor RAMA: and his intention is to return it (Tur). This is specifically to the top [of the stove] but to the inside it is forbidden. It is forbidden to return [a pot] to a Tanur even if it is raked and covered up. Similarly, a Kupach when fired with Gefes [olive waste] and wood. RAMA: This is specifically when the food is fully cooked (Beis Yosef). It is then permitted to return it, even to another Kirah. But if it is not fully cooked it is forbidden even to return it to the same Kirah. There are those who say that all is forbidden only where one removes it from the Kirah while it is still day and wishes to return it after dark. However, if he removes it after dark it is permitted [to return] even if in the meantime he places it on the floor. (R"an Perek Kirah). This is our custom to be lenient for our [type of] ovens, that have the status of a Kirah, because the lenient opinion is relied upon. And it is better to be more stringent. But in all opinions where it has cooled off it is forbidden [to return it] [Beis Yosef]. There are those who say that if one removes the food from the Tanur on Shabbos it is forbidden to wrap it up in pillows or blankets. There are those who say that close to dark or close to Barchu which for us constitutes an acceptance of Shabbos (Ha'agahot Mordechai), where it is so close to Shabbos that if the pot would be cool it would be impossible to boil it up while still day, the same law (of Chazora) applies as to Shabbos itself. Some are lenient in this, and such is the accepted practice. Nevertheless it would be preferable to be stringent where there is no real need. But this refers only (to returning) directly onto a Kirah, however placing it next to it (the stove) or even next to a fire where the heat is Yad soledes bo is permitted even close to dusk. For a Tanur there is no difference between returning a pot onto it or next to it when that area is at a temperature of Yad soledes bo, but if that area is not Yad soledes it is permitted even on Shabbos, as will be stated below in Siman 318.

Chazara, Shiyah: The halachos of returning food to the fire on shabbos.

Borer: The premise of Borer- It must be a immediately

Borer: separating food on your plate to make space for other food

Borer: The premise of Borer - two different types part 2

Borer: The premise of Borer - two different types

Borer: Second Condition of Borer - Taking the good from the bad part 5 moving the top to get to the bottom

Borer: Second Condition of Borer - Taking the good from the bad part 4 solids from liquids

Borer: Second Condition of Borer - Taking the good from the bad part 3 silverware

Borer: Second Condition of Borer - Taking the good from the bad part 2 Cleaning dirt from fruits

Borer: Second Condition of Borer - Taking the good from the bad

Borer: The premise of Borer- It must be a mixture part 3 (bones in the fish)

Borer: The premise of Borer- It must be a mixture part 2

Borer: The premise of Borer- It must be a mixture

Borer: Third Condition of Borer - Immediate use (part2)

Chazara, Shiyah: The halachos of returning food to the fire on shabbos.

Hilchos Muktzah #3

The Laws of renting a field and a bath to a goy on shabbos

Asking A goy to do work on shabbos