Numbers 9:4-6

Darby Translation

⁴ And Moses spoke to the children of Israel, that they should hold the passover.

⁵ And they held the passover in the first [month] on the fourteenth day of the month, between the two evenings, in the wilderness of Sinai: according to all that Jehovah had commanded Moses, so did the children of Israel.

⁶ And there were men, who were unclean through the dead body of a man, and could not hold the passover on that day; and they came before Moses and before Aaron on that day.