Numbers 3:42

3:42 So Moses numbered all the firstborn males among the Israelites, as the Lord had commanded him.

Numbers 3:40

The Substitution for the Firstborn

3:40 Then the Lord said to Moses, “Number all the firstborn males of the Israelites from a month old and upward, and take ¹  the number of their names.

Numbers 1:20

1:20 And they were as follows:

The descendants of Reuben, the firstborn son of Israel: According to the records of their clans and families, all the males twenty years old or older who could serve in the army were listed by name individually.

Numbers 3:41

3:41 And take ²  the Levites for me – I am the Lord – instead of all the firstborn males among the Israelites, and the livestock of the Levites instead of all the firstborn of the livestock of the Israelites.”

[3:40]  ¹ tn The verb נָשָׂא (nasa’, “take”) has here the sense of collect, take a census, or register the names.

[3:41]  ¹ tn The verb is the perfect tense with vav (ו) consecutive; it carries forward the instructions from the preceding verse. The verb “take” now has the sense of appointing or designating the Levites.