- Question: What is the difference between putting a clay vessel in the oven right before Shabbos to finish hardening which Rashi in Shabbos 74b says does not constitute breaking Shabbos under the prohibition of makeh b’patish, i.e. giving the final blow to create an object, since the oven is doing it by itself and you are doing nothing to finish it, whereas the Even Ha’Ozer (Orach Chaim 328) says that putting in wheat kernels to be ground on Shabbos by a mill running on water does constitute breaking shabbos and is forbidden (according to him on a Torah level and according to the Magen Avraham on a Rabbinic level) even though you aren’t directly grinding, the water is causing the machine to grind for you?
- The issue with the melacha of techina/grinding is the action of grinding.
- The issue with the melacha of makeh bipatish/doing the final blow is the result of a finished product.
Answer: You are responsible for causing the machine to grind by putting the kernels into the machine for it to be ground by the water since the issue is the action itself which you caused the machine to do so it is directly related to you since caused the water to start the process. Whereas by the clay vessel you just placed the vessel in the oven and the oven finished the job by itself, so since the issue is not the action the oven did but the results that it created then you aren’t directly responsible for what happened.