Numbers 9:13-14

13But perhaps a clean person who is at home chooses not to eat the Passover meal. You must make that person separate from his people. That is because he did not offer the proper sacrifices to the Lord at the proper time. So that person must receive the punishment for his sin.

14People from foreign countries may also eat the Lord's Passover meal, if they are living among you. But they must obey all the rules about the Passover festival. The rules are the same for a foreign person and for an Israelite.” ’