Numbers 9:1-3

1Now the Lord spoke to Moses in the wilderness of Sinai, in 1the first month of the second year after they had come out of the land of Egypt, saying,

2“Now the sons of Israel are to 2celebrate the Passover at 3its appointed time.

3On the fourteenth day of this month, 4at twilight, you shall celebrate it at its appointed time; you shall celebrate it in accordance with all its statutes and all its ordinances.”