Numbers 1:2

“Take ye the sum of all the congregation of the children of Israel, etc.] Excepting the Levites; nor were any account taken of the mixed multitude that came out of Egypt with the children of Israel, only of them; and this account was taken, partly to observe the fulfilment of the divine promise to Abraham concerning the multiplication of his seed, and partly that it might be observed, that at the end of thirty eight years from hence, when they were numbered again, there were but three left of this large number, their carcasses falling in the wilderness because of their sins; and chiefly, as Aben Ezra observes, this sum was now taken to fix their standards, and for their better and more…”

“A month had passed away since the setting up of the tabernacle Exodus 40:2, Exodus 40:17 : and the Sinaitic legislation was now complete (compare Leviticus 27:34). A census (“sum”) was commanded, to be based not upon any fresh registration of individuals, but upon that which had accompanied the previous collection of the offerings. Compare Exodus 30:11, etc.; Exodus 38:25-28. The offerings had been probably tendered by the people in groups, and if certificates of registration were furnished to such groups, the new census might be easily carried out by means of these documents, and got through Numbers 1:18 in a single day. The present registration enrolled persons “after their families, by…”

“Take the sum - This is not the same muster with that Exo 38:26, as plainly appears, because that was before the building of the tabernacle, which was built and set up on the first day of the first month, Exo 40:2, but this was after it, on the first day of the second month. And they were for different ends; that was to tax them for the charges of the tabernacle; but this was for other ends, partly that the great number of the people might be known to the praise of God's faithfulness, in making good his promises of multiplying them, and to their own encouragement: partly for the better ordering their camp and march, for they were now beginning their journey; and partly that this account might…”

“1:2-16 men twenty years old or older who are able to go to war: In this effort to register Israel’s men of military age, more information was gathered than in the previous registration (cp. Exod 38:26). • the tribes and the names of the leaders: Hebrew culture was tribal, built around clans and families. The tribal leaders were readily identified and appear again as a group in Num 7. • Moses and Aaron did not include Levi’s tribe in this registration, since it had a special status in Israelite society (cp. 1:47-53; 26:51-62; Deut 18:5; 33:8-11).”

“Take ye the sum: This numbering was probably intended to illustrate the Divine faithfulness in thus increasing the seed of Abraham; to prepare them to preserve due order in their march; and to distinguish the tribes and families. Num 26:2-4, Num 26:63, Num 26:64; Exo 30:12, Exo 38:26; Sa2 24:1-3; Ch1 21:1, Ch1 21:2, Ch1 27:23, Ch1 27:24 the children: Gen 49:1-3; Exo 1:1-5 after: Num 1:18, Num 1:22, 26-54; Exo 6:14-19 Numbers 1:3”