Pesahim

Pesachim (, lit. "Paschal lambs" or "Passovers"), also spelled Pesahim, is the third tractate of Seder Moed ("Order of Festivals") of the Mishnah and of the Talmud. The tractate discusses the topics related to the Jewish holiday of Passover, and the Passover sacrifice, both called "Pesach" in Hebrew. The tractate deals with the laws of matza (unleavened bread) and maror (bitter herbs), the prohibitions against owning or consuming chametz (leaven) on the festival, the details of the Paschal lamb that used to be offered at the Temple in Jerusalem, the order of the feast on the first evening of the holiday known as the Passover seder, and the laws of the supplemental "Second Pesach".

Two reasons are given for the name of the tractate Pesachim being in the plural: either because the tractate originally comprised two parts, one dealing with the Passover sacrifice, and the second with the other aspects of the holiday, before they were combined into a single tractate named Pesachim during the Geonic period (by 1040 CE), or, because the tractate deals with the two occasions for offering the Passover sacrifice, namely, the 14th of the month of Nisan on the eve of the holiday, and one month later, the "second Pesach" on the 14th of Iyar for those who were unable to offer the sacrifice on the original date.