Numbers 9:1-3

BBE^{(i) 1} And the Lord said to Moses, in the waste land of Sinai, in the first month of the second year after they had come out of the land of Egypt, ² Let the children of Israel keep the Passover at its regular time. ³ In the fourteenth day of this month, at evening, you are to keep it at the regular time, and in the way ordered in the law.