Exodus 12:5-8

Your lamb shall be an unblemished male a year old; you may take it from the sheep or from the goats. You shall keep it until the fourteenth day of the same month, then the whole assembly of the congregation of Israel is to kill it at twilight. Moreover, they shall take some of the blood and put it on the two doorposts and on the lintel of the houses in which they eat it. They shall eat the flesh that same night, roasted with fire, and they shall eat it with unleavened bread and bitter herbs.