Numbers 9:5-7

New Century Version

⁵ and they did; it was in the Desert of Sinai at twilight on the fourteenth day of the first month. The Israelites did everything just as the Lord commanded Moses.

⁶ But some of the people could not celebrate the Passover on that day because they were unclean from touching a dead body. So they went to Moses and Aaron that day and ⁷ said to Moses, “We are unclean because of touching a dead body. But why should we be kept from offering gifts to the Lord at this appointed time? Why can’t we join the other Israelites?”