Commentaire de citation sur Samuel 1 13:15

Here it teaches you. . . [How does Rashi know this?] Because it is written מבן עשרים שנה , so why does it need to say also כל העובר על הפקודים ? Perforce, because “here it teaches you. . .” The term פקודים is used for the army, as in (Bamidbar 31:14), “Moshe was angry with the commanders ( פקודי ) of the army,” and as in (Shmuel I 13:15), “Shaul counted ( ויפקוד ) the people [of the army].” Thus, our verse uses the term הפקודים to tell us “that no one below twenty years of age goes into the army.” Accordingly, the passage means: “When you take the count of the B’nei Yisrael to go into the army for war, they shall be from twenty years and older.” You might ask: Why do we need to be taught here [by inference] that no one below twenty goes into the army? We were already taught this [expressly]: “From twenty years old and above, all those eligible for the army” (Bamidbar 1:3). The answer is: We might think Scripture was particular [about age] only regarding obligatory wars [such as the conquest of Eretz Yisrael], but not regarding optional wars [such as the conquest of surrounding lands]. Thus Scripture repeated it, [to teach that] for optional wars also, no one below twenty goes out to war.