Numbers 9:3-5

ASV(i) 3 In the fourteenth day of this month, at even, ye shall keep it in its appointed season: according to all the statutes of it, and according to all the ordinances thereof, shall ye keep it. 4 And Moses spake unto the children of Israel, that they should keep the passover. 5 And they kept the passover in the first [month], on the fourteenth day of the month, at even, in the wilderness of Sinai: according to all that Jehovah commanded Moses, so did the children of Israel.