Exodus 12:3, 5-6

Speak ye unto all the congregation of Israel, saying, In the tenth day of this month they shall take to them every man a lamb, according to their fathers’ houses, a lamb for a household

Your lamb shall be without blemish, a male a year old: ye shall take it from the sheep, or from the goats: and ye shall keep it until the fourteenth day of the same month; and the whole assembly of the congregation of Israel shall kill it at even.