Kommentar zu Schemot 12:20

מחמצת לא תאכלו THAT WHICH LEAVENETH YE SHALL NOT EAT — Here we have the prohibition regarding eating שאור (that which causes food to become leavened).

ANYTHING THAT IS LEAVENED YE SHALL NOT EAT. “This includes food with which leaven is mixed.” Thus the language of Rashi.
This too is not in accordance with the final decision of the law, for the adopted opinion is like that of the Sages who say that the penalty incurred for eating leavened food is extinction, but for food with an admixture of leaven, there is no specific verse that includes it, [although it is nevertheless forbidden].²²⁵Why then did Rashi interpret the verse in accordance with the opinion of a single Sage — Rabbi Eliezer — when the Sages who are the majority differ with him? Commentators, however, have shown that the accepted final decision of the law in this case is in accordance with the opinion of Rabbi Eliezer. Maimonides and other scholars have all accepted the decision of Rabbi Eliezer. See my Hebrew commentary, p. 333.

בכל מושבותיכם תאכלו מצות, even outside the city of Jerusalem, although the Passover itself must not be slaughtered outside Jerusalem.