The Lord spoke to Moses in the wilderness of Sinai, on the first new moon of the second year following the exodus from the land of Egypt, saying: Let the Israelite people offer the passover sacrifice at its set time: you shall offer it on the fourteenth day of this month, at twilight, at its set time; you shall offer it in accordance with all its rules and rites.
Moses instructed the Israelites to offer the passover sacrifice; and they offered the passover sacrifice in the first month, on the fourteenth day of the month, at twilight, in the wilderness of Sinai. Just as the Lord had commanded Moses, so the Israelites did. But there were some men who were unclean by reason of a corpse and could not offer the passover sacrifice on that day. Appearing that same day before Moses and Aaron, those men said to them, "Unclean though we are by reason of a corpse, why must we be debarred from presenting the Lord's offering at its set time with the rest of the Israelites?" Moses said to them, "Stand by, and let me hear what instructions the Lord gives about you."
And the Lord spoke to Moses, saying: Speak to the Israelite people, saying: When any of you or of your posterity who are defiled by a corpse or are on a long journey would offer a passover sacrifice to the Lord, they shall offer it in the second month, on the fourteenth day of the month, at twilight. They shall eat it with unleavened bread and bitter herbs, and they shall not leave any of it over until morning. They shall not break a bone of it. They shall offer it in strict accord with the law of the passover sacrifice. But if a man who is clean and not on a journey refrains from offering the passover sacrifice, that person shall be cut off from his kin, for he did not present the Lord's offering at its set time; that man shall bear his guilt.
And when a stranger who resides with you would offer a passover sacrifice to the Lord, he must offer it in accordance with the rules and rites of the passover sacrifice. There shall be one law for you, whether stranger or citizen of the country.