Numbers 9:1-3

King James Version

9 And the Lord spake unto Moses in the wilderness of Sinai, in the first month of the second year after they were come out of the land of Egypt, saying,

² Let the children of Israel also keep the passover at his appointed season.

³ In the fourteenth day of this month, at even, ye shall keep it in his appointed season: according to all the rites of it, and according to all the ceremonies thereof, shall ye keep it.