Numbers 9:13-14

13But if you are clean  and not on a trip and yet don’t bother to celebrate the Passover, you must be excluded from the people. You didn’t bring your offering to the Lord at the right time. You must suffer the consequences for your sin.

14“Foreigners living with you may want to celebrate the Lord’s Passover. They must follow these same rules and regulations. The same rules will apply to foreigners and native-born Israelites.”