Exodus 12:1-5

The LORD spoke to Moses and Aaron in the land of Egypt: “This month will be the beginning of months, the first month of the year for you. Tell the whole community of Israel that on the tenth day of this month each man must get one lamb for the people in his house. If there are not enough people in his house to eat a whole lamb, he must share it with his closest neighbor, considering the number of people. There must be enough lamb for everyone to eat. The lamb must be a one-year-old male that has nothing wrong with it. This animal can be either a young sheep or a young goat.