Menahot, Chapter Five, Mishnah Two
Our mishnah deals with the prohibition of allowing a minhah to become hametz, for as we learned in yesterdays mishnah, nearly all minhahs must be brought as matzot.
1) All minhahs must be kneaded with lukewarm water and must be watched lest they become leavened.
2) If one allowed the remainder to become leavened he has transgressed a negative commandment, for it is written, No minhah which you shall bring to the Lord shall be made leavened (Leviticus 2:11).
3) One is liable for the kneading, and for rolling and for baking.
Section one: In order to delay the leavening process, the minhah was kneaded with lukewarm water, and it was carefully watched so that it would not become leaven.
Section two: Even the remainders of the minhah, the part of the minhah eaten by the priests, were not allowed to become leaven. If one did allow any part of the minhah to become leaven, he transgressed the negative commandment found in Leviticus 2:11.
Section three: If a minhah becomes leaven and one performs any one of these acts, kneading, rolling the dough or baking it, he is liable.