In order for the Israelites to avoid being harmed by the tenth plague, it was vital for them to obey instructions. (Ex 12:28) On the night of Nisan 14, families were to assemble in their own home. They were to kill a sound one-year-old male lamb or goat. Its blood was to be sprinkled on the doorposts and on the upper part of the doorway. Then they were to roast the entire animal and eat it in a hurry. No one was to go out of the house until morning.​—Ex 12:9-11, 22.