פירוש על שמות 24:5

את נערי THE LADS — the first-born sons (Zevachim 115b; Onkelos).

AND HE SENT ‘NA’AREI’ (THE YOUNG MEN OF) THE CHILDREN OF ISRAEL. These were the firstborns, as Onkelos rendered it, for it was they who used to offer the burnt-offerings and the peace-offerings. But I do not know why Scripture designates the firstborns by the term na’arei (the young men)? Perhaps it is because Scripture mentioned the elders who are the nobles of the children of Israel,⁵¹⁹Further, Verse 11. therefore it called the firstborns ne’arim (young men), for in relation to the elders they were young. It thus indicates that Moses sent them to offer the sacrifices not because of their status in wisdom, for they were not yet advanced in age, but only an account of the birthright, through which they were set aside to offer sacrifices.
In line with the plain meaning of Scripture, the young men of the children of Israel were the youth of Israel who had not tasted of sin,⁵²⁰Erubin 21b. and had never come near a woman, for they were the most select and holy of the people, in a similar manner to that which the Rabbis have said:⁵²¹Berachoth 43b. “The young men of Israel who have not tasted of sin⁵²²“Who have not tasted of sin” is not found in our Gemara, but it is present in manuscripts of the Talmud and other early works (see Dikdukei Sofrim, ibid., Note 6). are destined to give forth a fragrance like the Lebanon etc.”⁵²³“As it said, His branches shall spread, and his beauty shall be as the olive-tree, and his fragrance as Lebanon (Hosea 14:7)” (ibid). The word Lebanon [of the root lavan — white] is an allusion here to the Sanctuary which “whitens” [atones for] the sins of Israel. The thought suggested then is that these young men who have not tasted of sin are as beneficial to Israel as the Sanctuary (Maharsha).

את נערי בני ישראל, the firstborns of each family.