And the LORD spake unto Moses in the wilderness of Sinai, in the tabernacle of the congregation, on the first day of the second month, in the second year after they were come out of the land of Egypt, saying,
On the first day ... Thirteen months had elapsed since the exodus. About one month had been occupied in the journey; and the rest of the period had been passed in encampment among the recesses of Sinai, where the transactions took place, and the laws, religious and civil, were promulgated, which are contained in the two preceding books. Since the tabernacle was erected on the first day of the first month, and the order here mentioned was given on the first day of the second, some think the laws in Leviticus were all given in one month.
The Israelites having been formed into a separate nation, under the special government of God as their King, it was necessary, before resuming their march toward the promised land, to put them into good order. And accordingly Moses was commissioned, along with Aaron, to take a census of the people. This census was incidentally noticed (see the note at Exodus 38:26, where different theories of explaining the exact agreement in numbers between the poll-tax registration and the military census are noticed) in reference to the poll-tax for the works of the tabernacle; but it is here described in detail, in order to show the relative increase and military strength of the different tribes.
After their families, by the house of their fathers, with the number of their names, every male by their polls. The people of Israel were arranged into three great graduated bodies х maTowt (H4294), or shibaTiym (H7626), tribes; mishpaachowt (H4940), families; and beeyt (H1004) 'abowt (H1), house of fathers]. In accordance with this organic division the census in the wilderness was taken; and as the people were registered individually by name, an exact muster-roll was formed, and, as appears from one recorded incident (Joshua 7:16-26), was systematically kept of the whole nation under the heads of thousands, hundreds, tens, and units, corresponding with the respective tribes, families, households, and individuals composing it. Rulers were appointed over these several sections of the people, having jurisdiction within their own sphere, while the highest of these acted as assistants of Moses and Aaron in the furtherance of measures that affected the general interest (Numbers 27:2; Deuteronomy 29:10).