Numbers 9:1

And the Lord spake unto Moses in the wilderness of Sinai
While the people of Israel were encamped there, before they took their journey from thence: in the first month of the second year, after they were come out of the
land of Egypt:
the following order was given some time in the first month of the second year of Israel's departure out of Egypt; the precise day is not mentioned, it must be in the beginning of the month before the fourteenth day of it, in which the passover is ordered to be kept, according to the first institution of it; very probably immediately after the setting up of the tabernacle, and the consecration of Aaron and his sons; and it must be before the numbering of the people the fixing of their standards, the appointment of the Levites, and the dedication of them; since the order for the numbering of the people was on the first day of the second month, ( Numbers 1:1 ) , but the account of them was postponed to this time, in order to give a relation of an affair which was not finished until the second month, and therefore the whole is laid together here: saying,
as follows.