Verse 4: Then Joshua called the twelve men, whom he had prepared of the children of Israel, out of every tribe a man…
[Whom he had chosen, אֲשֶׁ֥ר הֵכִ֖ין] Whom he had prepared (Syriac), he had made ready (Masius, similarly Montanus), because he had commanded them to be present, ready at an instant (Masius), he had appointed (Arabic).
Prepared, that is, appointed or chosen for that work, and commanded them to be ready for it.
Verse 5: And Joshua said unto them, Pass over before the ark of the LORD your God into the midst of Jordan, and take ye up every man of you a stone upon his shoulder, according unto the number of the tribes of the children of Israel…
Pass over before the ark, that is, go back again to the place where the ark stands.
[Stones] Concerning this kind of monument, see Genesis 31:46 and Joshua 4:21 (Grotius).
 Hebrew: וַיִּקְרָ֣א יְהוֹשֻׁ֗עַ אֶל־שְׁנֵ֤ים הֶֽעָשָׂר֙ אִ֔ישׁ אֲשֶׁ֥ר הֵכִ֖ין מִבְּנֵ֣י יִשְׂרָאֵ֑ל אִישׁ־אֶחָ֥ד אִישׁ־אֶחָ֖ד מִשָּֽׁבֶט׃
 Hebrew: וַיֹּ֤אמֶר לָהֶם֙ יְהוֹשֻׁ֔עַ עִ֠בְרוּ לִפְנֵ֙י אֲר֧וֹן יְהוָ֛ה אֱלֹֽהֵיכֶ֖ם אֶל־תּ֣וֹךְ הַיַּרְדֵּ֑ן וְהָרִ֙ימוּ לָכֶ֜ם אִ֣ישׁ אֶ֤בֶן אַחַת֙ עַל־שִׁכְמ֔וֹ לְמִסְפַּ֖ר שִׁבְטֵ֥י בְנֵי־יִשְׂרָאֵֽל׃