Deuteronomy 3:18
And I commanded you at that time, saying, The LORD your God hath given you this land to possess it: ye shall pass over armed before your brethren the children of Israel, all that are meet for the war.
And I commanded you at that time,.... Not all Israel, but the tribes of Reuben and God, and the half tribe of Manasseh; for what follows only concerns them:
saying, The LORD your God hath given you this land to possess it; the land before described, lately in the hands of Sihon and Og; this at their request Moses gave them, by the direction of the Lord, on the following condition:
you shall pass over armed before your brethren the children of Israel, all that are meet for the war; that is, they should pass over Jordan with the rest of the tribes, being armed to assist them in the conquest of Canaan: for this phrase, which we render "before your brethren", does not signify that they went in the forefront of them, only that they were present with them, and joined them in their war against their enemies; see Numbers 32:29 and therefore should be rendered "with your brethren" {a}; even as many of them as were able to bear arms, at least as many as Joshua would choose to take of them; for he did not take them all by a great many; see Joshua 4:13.
{a} Mkyxa ynpl "cum fratribus vestris", Noldius, p. 531, No. 1492.