Numbers 3:1

1.These also are the generations of Aaron and Moses He now separately enumerates the Levites; but, before he proceeds to state their number, he first shortly refers to what he had just before more fully narrated, that of the four sons of Aaron only two survived their father, inasmuch as Nadab and Abihu had suffered the penalty of their negligence in their defilement of the sacrifice. The six verses (423) which Moses inserts respecting the office of the priests have been expounded in their proper place. The dignity of the tribe of Levi is here exalted, when God compares the Levites to the first-born; the distribution of their charges is also touched upon, (424) but, since these things are connected with the census of the people, and the mode of pitching the camp, I have thought it best to annex them to what has just preceded, inasmuch as otherwise the history would be interrupted. And, in fact, in the order that I have followed, the office of each family is only incidentally treated of, so that all might know their proper station.