Numbers 9:10-12

“Tell the Israelites: When any one of you or your descendants is unclean because of a corpse or is on a distant journey, he may still observe the Passover to the LORD. Such people are to observe it in the second month, on the fourteenth day at twilight. They are to eat the animal with unleavened bread and bitter herbs; they may not leave any of it until morning or break any of its bones. They must observe the Passover according to all its statutes.