Exodus 12:48-49

48There may be a foreign person who lives among you. He may want to join you to eat the Lord's Passover meal. But he must first be circumcised as well as all the men in his house. Then he can join with you and eat the Passover meal. He will be like a man who has been born in Israel. But no male person without circumcision can join the Passover feast.

49Both the people who were born as Israelites and the foreign people who live among you must obey this rule.’