וְעַתָּ֗ה קְח֤וּ לָכֶם֙ שְׁנֵ֣י עָשָׂ֣ר אִ֔ישׁ מִשִּׁבְטֵ֖י יִשְׂרָאֵ֑ל אִישׁ־אֶחָ֥ד אִישׁ־אֶחָ֖ד לַשָּֽׁבֶט׃
Now select twelve individuals from the tribes of Israel, one from each tribe.
(The above rendering comes from the RJPS translation, an adaptation of the NJPS translation. Before accounting for this rendering, I will analyze the plain sense of the Hebrew term containing אִישׁ.)
In its second and third instances in this verse, אִישׁ is employed as a situating noun, to describe the manner of carrying out the desired selection.
The referents are situated in relation not only to the act of Joshua’s making a choice, but also to the group that they are to be individuated from: their tribe.
Gender is not at issue (for the intended role of these participants, see below, 4:2–3).
As for rendering into English, there is no warrant for rendering in gendered terms, because it goes without saying (see previous comment to this verse). In present parlance, the NJPS rendering as ‘one man’ overstates maleness.
For RJPS, after removing the noun ‘man’, the adjective ‘one’ still expresses participation and representation adequately, due to the preposition that follows.