Bamidbar 1:17-19

Orthodox Jewish Bible

¹⁷ And Moshe and Aharon took these men which had been designated by their names;

¹⁸ And they assembled kol HaEdah together on the first yom of the second month, and they declared their family after their mishpekhot, by the bais of their avot, according to the number of the shmot, from twenty years old and upward, one by one.

¹⁹ As Hashem commanded Moshe, so he counted them in the midbar of Sinai.