Exodus 12:3-8

³Tell all the Israelites that on the tenth day of this month, every man must choose a lamb for his family, one for each household.

⁴However, if the household is too small for a whole lamb, then he and his nearest neighbor may choose a lamb according to the total number of people. Divide up the lamb depending on what everybody can eat.

⁵Your lamb must be a year-old male without any defects, and you can take it either from the sheep or the goats.

⁶Keep it until the fourteenth day of the month, when all the Israelites will slaughter the animals after sunset and before it gets dark.

⁷They are to take some of the blood and put it on the sides and tops of the doorframes of the houses where they have the meal.

⁸They are to roast the meat over a fire and eat it that night, together with unleavened bread and bitter herbs.