Chapter 3, Mishna 4, 5, 6 Rabbah and Rav Hisda debate whether we employ the principle of “since” as an escape clause from a liability for certain transgressions. Rabbah says yes, Rav Hisda says no. Is this the root of the debate between Rabbi Eliezer and Rabbi Yehoshua on what to do with the consecrated challah portion of tamei, ritually impure, matzah dough on the first day of Passover? How do three women divide the labor of when baking matzah together to ensure their dough never has a chance to leaven? What are the visible signs that dough has become leavened?