Exodus 12:3-6

3Tell the whole congregation of Israel that on the tenth day of this month each man must select a lamb1 for his family, one per household. 4If the household is too small for a whole lamb, they are to share with the nearest neighbor based on the number of people, and apportion the lamb accordingly.

5Your lamb must be an unblemished year-old male, and you may take it from the sheep or the goats. 6You must keep it until the fourteenth day of the month, when the whole assembly of the congregation of Israel will slaughter the animals at twilight.2