Numbers 9:8

5 So they kept the Passover in the first month, on the fourteenth day of the month, at evening, in the waste land of Sinai: as the Lord gave orders to Moses, so the children of Israel did.

6 And there were certain men who were unclean because of a dead body, so that they were not able to keep the Passover on that day; and they came before Moses and before Aaron on that day:

7 And these men said to him, We have been made unclean by the dead body of a man; why may we not make the offering of the Lord at the regular time among the children of Israel?

8 And Moses said to them, Do nothing till the Lord gives me directions about you.

9 And the Lord said to Moses,

10 Say to the children of Israel, If any one of you or of your families is unclean because of a dead body, or is on a journey far away, still he is to keep the Passover to the Lord:

11 In the second month, on the fourteenth day, in the evening, they are to keep it, taking it with unleavened bread and bitter-tasting plants;