Exodus 12:1-13

And Jehovah spake unto Moses and Aaron in the land of Egypt, saying, This month shall be unto you the beginning of months: it shall be the first month of the year to you. 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: and if the household be too little for a lamb, then shall he and his neighbor next unto his house take one according to the number of the souls; according to every man’s eating ye shall make your count for the lamb. 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. And they shall take of the blood, and put it on the two side-posts and on the lintel, upon the houses wherein they shall eat it. And they shall eat the flesh in that night, roast with fire, and unleavened bread; with bitter herbs they shall eat it. Eat not of it raw, nor boiled at all with water, but roast with fire; its head with its legs and with the inwards thereof. And ye shall let nothing of it remain until the morning; but that which remaineth of it until the morning ye shall burn with fire. And thus shall ye eat it: with your loins girded, your shoes on your feet, and your staff in your hand; and ye shall eat it in haste: it is Jehovah’s passover. For I will go through the land of Egypt in that night, and will smite all the first-born in the land of Egypt, both man and beast; and against all the gods of Egypt I will execute judgments: I am Jehovah. And the blood shall be to you for a token upon the houses where ye are: and when I see the blood, I will pass over you, and there shall no plague be upon you to destroy you, when I smite the land of Egypt.