Stoking the Coals

There is a principle related to the laws of Shabbat called, שמא יחתה בגחלים, lest he stoke the coals.

This applied largely to the ovens during Talmudic times. They were heated with coals and when food was not fully cooked, a person might inadvertently stoke the coals to increase the heat. This is a serious Shabbat violation of a מלאכה.

The aspect of this law that is applicable today, would be making a bonfire before Shabbat, to use to keep warm on Shabbat. The bonfire must be an already strong flame as Shabbat commences, for otherwise, one may come to stoke the coals, שמא יחתה בגחלים.

There are exceptions to this rule in situations where there is no worry of stoking the coals. One example was a fire burned in בית המוקד, the dormitory like structure for Kohanim while they served in the Beit Hamikdash. They made a bonfire to keep warm that did not have to be such a strong flame.

Because Kohanim are זריזים, and act with alacrity, they will remind one another not to stoke the coals.

Similarly, when the קרבן פסח was placed on the spit to roast over the coals, when Pesach fell on Friday night, there was also no fear of a Shabbat violation, because all of the members of the group sharing in the קרבן פסח, would remind one another not to stoke the coals.