Introduction This mishnah deals with an animal set aside to be a pesah that gets mixed up with other animals set aside to be other sacrifices. We should note that this is a common theme that the Mishnah just loves to discuss different animals or items of different statuses getting mixed up with each other.
If a pesah became mixed up with other sacrifices, they all graze until they become unfit [through a blemish], then they are sold, and then he must bring [a replacement] for the price of the best of this type, and bring for the price of the best of this type and he loses the remainder from his own pocket. In this case the pesah gets mixed up with other animals that are set aside for other sacrifices. The rules and restrictions concerning each of these sacrifices may be different: their blood is sprinkled differently on the altar and their meat is eaten for a different period of time. Since we don’t know which animal was set aside for which sacrifice, none of them may be sacrificed. All of the animals must be sold and then the proceeds used to purchase new sacrifices. However, the way in which the new sacrifices are bought is somewhat complicated. Every new purchase must be made at the value of the most expensive of the mixed-up animals, lest that sacrifice was from that expensive animal. For instance, three lambs were set aside for three different sacrifices and then were mixed up. When he sells them, one lamb sells for two zuzim (had gadya, had gadya, dizban Abba b’tre zuze) and the other two lambs sell for one zuz each (if you know Aramaic this would be dizban Abba b’zuza hada). When he buys replacement sacrifices he must buy three lambs worth two zuz each, because he doesn’t know which sacrifice was from the more expensive lamb. This loss of money (two zuzim) is made up from his own pocket.
If it became mixed up with first-borns: Rabbi Shimon says: if [the pesah belonged to] a company of priests, they eat [all of the animals that night]. In this case the pesah becomes mixed up with firstborn animals. Generally, the firstborn of a sheep or goat (or other kosher animal) must be given to the priest. The animal is slaughtered and its blood is sprinkled on the altar and then it may be eaten by priests. The sprinkling of the blood for the firstborn is performed in the same was as that of the pesah. Therefore, the mishnah rules that if the company of people registered to eat the pesah are priests, they may eat these animals on Pesah as if they were valid pesahim. In other words, they can treat all of the animals as if they were all pesahim. However, they can only eat them that night, because a pesah cannot be left over till morning.