40 Yahweh said to Moses, "Number all the firstborn males of the children of Israel from a month old and upward, and take the number of their names.
then Moses stood in the gate of the camp, and said, "Whoever is on Yahweh's side, come to me!" All the sons of Levi gathered themselves together to him. He said to them, "Thus says Yahweh, the God of Israel, 'Every man put his sword on his thigh, and go back and forth from gate to gate throughout the camp, and every man kill his brother, and every man his companion, and every man his neighbor." The sons of Levi did according to the word of Moses: and there fell of the people that day about three thousand men. Moses said, "Consecrate yourselves today to Yahweh, yes, every man against his son, and against his brother; that he may bestow on you a blessing this day."
Worthy.Bible » Commentaries » Matthew Henry Commentary » Commentary on Numbers 3
Commentary on Numbers 3 Matthew Henry Commentary
Chapter 3
This chapter and the next are concerning the tribe of Levi, which was to be mustered and marshalled by itself, and not in common with the other tribes, intimating the particular honour put upon them and the particular duty and service required from them. The Levites are in this chapter considered,
Num 3:1-13
Here,
Num 3:14-39
The Levites being granted to Aaron to minister to him, they are here delivered to him by tale, that he might know what he had, and employ them accordingly. Observe,
Num 3:40-51
Here is the exchange made of the Levites for the first-born.