By Rabbi Berach Steinfeld
Shulchan Aruch, Orach Chaim 318:1 discusses if a person cooks on Shabbos or does any other melachah intentionally, it is forbidden to the person who did the aveira forever and to others it is muttar after Shabbos. If the person did it beshogeg, it is forbidden on Shabbos; however, on Motzai Shabbos it is muttar for both him and others right away. If someone did Borer and took out one food from another food it would stand to reason that the food is assur on Shabbos. What would happen if he remixes the food and it is as it was before? Would the food be permissible?
The gemara in
To answer the first question, the Pri Megadim in 319:1 and Shailos U
The Tzitz Eliezer 14:33 says we can’t compare it to a case of telling a goy, which is very stringent. We don’t want people being mezalzel in hilchos Shab
Regarding the mirror, we can differentiate that in all cases of writing even if it does not last there is some sort of ink that is applied. There is some kesiva involved if he is engraving something in the dirt, despite the fact that it does not last. Conversely, someone who looks in the mirror is not applying any material to the mirror and nothing is being engraved in the metal itself to make it considered ksiva. This would mean that a reflection is not a type of writing.
May we be zocheh to be mekayem Shabbos properly.
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