Numbers 9:2-5

2“Now, let the sons of Israel observe the Passover at 1its appointed time.

3On the fourteenth day of this month, 2at twilight, you shall observe it at its appointed time; you shall observe it according to all its statutes and according to all its ordinances.”

4So Moses 3told the sons of Israel to observe the Passover.

54They observed the Passover in the first month, on the fourteenth day of the month, at twilight, in the wilderness of Sinai; 5according to all that the Lord had commanded Moses, so the sons of Israel did.