Exodus 12:1-6 RSV

1 The LORD said to Moses and Aaron in the land of Egypt,
2 "This month shall be for you the beginning of months; it shall be the first month of the year for you.
3 Tell all the congregation of Israel that on the tenth day of this month they shall take every man a lamb according to their fathers' houses, a lamb for a household;
4 and if the household is too small for a lamb, then a man and his neighbor next to his house shall take according to the number of persons; according to what each can eat you shall make your count for the lamb.
5 Your lamb shall be without blemish, a male a year old; you shall take it from the sheep or from the goats;
6 and you shall keep it until the fourteenth day of this month, when the whole assembly of the congregation of Israel shall kill their lambs in the evening.