Exodus 12:5-8

The lamb must be a one-year-old male that has nothing wrong with it. This animal can be either a young sheep or a young goat. Take care of the animals until the fourteenth day of the month. On that day all the people of the community of Israel will kill them in the evening before dark. The people must take some of the blood and put it on the sides and tops of the doorframes of the houses where they eat the lambs. On this night they must roast the lamb over a fire. They must eat it with bitter herbs and bread made without yeast.