Numbers 9:6-7

6But there were certain men who were [ceremonially] unclean because of [touching] the dead body of a man, so they could not observe the Passover on that day; so they came before Moses and Aaron that same day.

7Those men said to Moses, “We are [ceremonially] unclean because of [touching] a dead body. Why are we being restrained from presenting the Lord’s offering at its appointed time among the Israelites?”