3:1-13 There was much work belonging to the priests' office, and there were now only Aaron and his two sons to do it; God appoints the Levites to attend them. Those whom God finds work for, he will find help for. The Levites were taken instead of the first-born. When He that made us, saves us, as the first-born of Israel were saved, we are laid under further obligations to serve him faithfully. God's right to us by redemption, confirms the right he has to us by creation.
And the Lord spake unto Moses,.... After he had given him the order for the numbering the children of Israel, and for the manner of their encampment and journeying:
saying; as follows.