Numbers 9:6-7

6However, there were some men who could not celebrate Passover because of being defiled by a dead body. So they came to Moses and Aaron on that same day,

7and these men said to him, “We have become unclean because of a dead man’s body. Why should we be kept from presenting the offering of Adonai at the appointed time with the rest of Bnei-Yisrael?”