Siman - Shabbos Daf 18

• Not putting wheat in a water mill erev Shabbos

There is a machlokes regarding the reason why one may not put wheat in a water mill erev Shabbos if it will continue working during Shabbos:

•Rabbah says it is because it makes a lot of noise which is a dishonor to Shabbos.

•Rav Yosef says it is due to the requirement to have one’s utensils rest on Shabbos (שביתת כלים).

•  Question whether kneading requires manual mixing

There is a machlokes in a Baraisa regarding what is required to make someone liable for the melacha of Losh (mixing):

• Rebbi holds that if one person contributes the flour and another puts in the water, the last one is liable since he is the once that causes the ingredients to bind together, even though no manual mixing was done.

• R’ Yosi, the son of R’ Yehuda holds that one is not liable until one actually kneads the dough manually.

• Placing food in the oven erev Shabbos

Beis Hillel prohibits placing a pot in an oven before Shabbos which will continue cooking during Shabbos, as a precautionary measure so that one will not come to stir the coals on Shabbos

(שמא יחתה). Therefore:

•A person may place a pot of raw food in the oven before Shabbos because the person wants it to cook through the night and there is no concern one will stir the coals.

•A person may place a pot of cooked food in the oven before Shabbos because there is no concern he will come to stir it.

•A person may not place a pot that contains food which is partially cooked food in the oven before Shabbos since there is a concern he will stir the coals. However, if he adds a raw piece of meat into the mixture, then it can be placed in the oven before Shabbos since the person will not come to stir it.