Numbers 9:7

4 And Moses spake unto the children of Israel, that they should keep the passover.

5 And they kept the passover on the fourteenth day of the first month at even in the wilderness of Sinai: according to all that the LORD commanded Moses, so did the children of Israel.

6 And there were certain men, who were defiled by the dead body of a man, that they could not keep the passover on that day: and they came before Moses and before Aaron on that day:

7 And those men said unto him, We are defiled by the dead body of a man: wherefore are we kept back, that we may not offer an offering of the LORD in his appointed season among the children of Israel?

8 And Moses said unto them, Stand still, and I will hear what the LORD will command concerning you.

9 And the LORD spake unto Moses, saying,

10 Speak unto the children of Israel, saying, If any man of you or of your posterity shall be unclean by reason of a dead body, or be in a journey afar off, yet he shall keep the passover unto the LORD.