וַיִּקְח֣וּ אֶת־צֵדָה֩ הָעָ֨ם בְּיָדָ֜ם וְאֵ֣ת שׁוֹפְרֹֽתֵיהֶ֗ם וְאֵ֨ת כׇּל־אִ֤ישׁ יִשְׂרָאֵל֙ שִׁלַּח֙ אִ֣ישׁ לְאֹֽהָלָ֔יו וּבִשְׁלֹשׁ־מֵא֥וֹת הָאִ֖ישׁ הֶחֱזִ֑יק...
So [the lappers] took the provisions and horns that the other men had with them, and he sent everyone else on Israel’s side back to their homes, retaining only the three hundred men.…
(The above rendering comes from the RJPS translation—an adaptation of the NJPS translation—showing a slight modification projected for October 2023. Before accounting for this rendering, I will analyze the plain sense of the Hebrew term containing אִישׁ.)
When a referring expression includes אִישׁ in construct with a group name, such as כָּל־אִישׁ יִשְׂרָאֵל֙, our noun marks its referent’s defining participation in the depicted situation. Here, in the context of intergroup hostilities, it labels the assembled militia in terms of their role as a party to the pending conflict with Midian. The militia’s members are construed as a unit—hence the singular noun. This usage regards them as one of the two opposing sides, as warring parties. Such “collective” usage of the singular was rare in the Bible up until now, but it occurs some two dozen times in the book of Judges. See already my comment at Josh 10:24.
As for rendering into English, the NJPS ‘the rest of the men of Israel’ nowadays places undue emphasis on masculinity. Furthermore, it relies upon an archaic sense of men as participants. On more properly rendering the Hebrew term into idiomatic English, see my comment at Josh 10:24. Meanwhile, the fact that women are not in view can go without saying, because it is self-evident from the military context.