He said - The reading in the Hebrew text is "they said." Joshua no doubt issued his orders through the "officers of the people" (compare Joshua 1:10).
Him that is armed - i. e. the warriors generally, not a division only. "The rereward" Joshua 6:9 was merely a detachment, and not a substantial portiere of the host; and was told off, perhaps, from the tribe of Daniel (compare the marginal reference) to close the procession and guard the ark from behind. Thus the order would be
(1) the warriors,
(2) the seven priests blowing the cornets,
(3) the ark,
(4) the rear-guard.

And he said unto the people, (f) Pass on, and compass the city, and let him that is armed pass on before the ark of the LORD.
(f) This is chiefly meant by the Reubenites, Gadites, and half the tribe of Manasseh.

And he said unto the people, pass on, and compass the city,.... The women and children, the young men under twenty years of age, the unarmed part of the camp, as distinguished from the armed men:
and let him that is armed pass on before the ark of the Lord; to guard the ark, protect the priests, and defend the people, should any sally be made by the enemy upon them. These seem to design all the males that were above twenty years of age able to bear arms, and fit for war; though some restrain it to the forty thousand of the tribes of Reuben, Gad, and Manasseh, Joshua 1:14.

Him that is armed - God would have them armed both for the defense of themselves and the ark, in case the enemies should make a sally upon them, and for the execution of the Lord's vengeance upon that city.