Exodus 12:1-6

1And the Lord spake unto Moses and Aaron in the land of Egypt, saying, 2This month shall be unto you the beginning of months: it shall be the first month of the year to you.

3Speak 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 the house of their fathers, a lamb for an house:1 4And if the household be too little for the lamb, let him and his neighbour next unto his house take it according to the number of the souls; every man according to his eating shall make your count for the lamb. 5Your lamb shall be without blemish, a male of the first year: ye shall take it out from the sheep, or from the goats:2 6And ye shall keep it up until the fourteenth day of the same month: and the whole assembly of the congregation of Israel shall kill it in the evening.3