Numbers 1:20 (BSB)

From the sons of Reuben, the firstborn of Israel, according to the records of their clans and families, counting one by one the names of every male twenty years of age or older who could serve in the army,

From Numbers 1. Also in the ESV.

Commentary on Numbers 1:20

• John Calvin (Reformed), Calvin's Commentaries on Numbers 1:20: 20. And the children of Reuben, Israel’s eldest son If any disputatious person should contend that one family could not increase in 250 years to so great an amount, and thus should reject as nebulous what surpasses the ordinary rule of nature, we must bear in mind what I have already stated, that, inasmuch as this increase depended on the power of God, nothing is...
• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on Numbers 1:17-43: We have here the speedy execution of the orders given for the numbering of the people. It was begun the same day that the orders were given, The first day of the second month; compare Num 1:18 with Num 1:1. Note, When any work is to be done for God it is good to set about it quickly, while the sense of duty is strong and pressing.
• John Gill (Reformed Baptist), Exposition of the Old and New Testaments on Numbers 1:20: And the children of Reuben, Israel's eldest son,.... Were numbered first, and next to them those of Simeon and Gad, for they were numbered according to the order in which they were to be encamped; for under Reuben's standard were Simeon and Gad, and under Judah's Issachar and Zebulun, and under Ephraim's Manasseh and Benjamin, and under Dan's Asher and Naphtali; and according to their...
• Jamieson-Fausset-Brown (Reformed), Commentary Critical and Explanatory on the Whole Bible on Numbers 1:20: These are those that were numbered--In this registration the tribe of Judah appears the most numerous; and accordingly, as the pre-eminence had been assigned to it by Jacob [Gen 49:8-12], it got the precedence in all the encampments of Israel. Of the two half-tribes of Joseph, who is seen to be "a fruitful bough" [Gen 49:22], that of Ephraim was the larger, as had been predicted.