'Rear guard' in the Bible

Then the standard of the camp of the descendants of Dan, who formed a rear guard for all the camps, set out according to their divisions; Ahiezer son of Ammishaddai [was] over its division.

And the armed [men] went before the priests who blew the trumpets, and the rear guard came after the ark, while they were blowing the trumpets.

The seven priests carrying the seven trumpets of the rams' horns before the ark of Yahweh went on continually, and they blew on the trumpets. And the armed [men] went before them, and [the] rear guard came after the ark of Yahweh, while the trumpets blew continually.

So they stationed the forces; all the army [was] north of the city while {the rear guard was west}. But Joshua went that night to the middle of the valley.

For you shall not go out in haste, and you shall not go in flight, for Yahweh [is] going before you, and your rear guard [is] the God of Israel.

Then your light shall break forth like the dawn, and your healing shall grow quickly. And your salvation shall go before you; the glory of Yahweh will be your rear guard.