'Rear guard' in the Bible

Then the standard of the camp of the sons of Dan, according to their armies, which formed the rear guard for all the camps, set out, with Ahiezer the son of Ammishaddai over its army,

The armed men went before the priests who blew the trumpets, and the rear guard came after the ark, while they continued to blow the trumpets.

The seven priests carrying the seven trumpets of rams’ horns before the ark of the Lord went on continually, and blew the trumpets; and the armed men went before them and the rear guard came after the ark of the Lord, while they continued to blow the trumpets.

So they stationed the people, all the army that was on the north side of the city, and its rear guard on the west side of the city, and Joshua spent that night in the midst of the valley.

But you will not go out in haste,Nor will you go as fugitives;For the Lord will go before you,And the God of Israel will be your rear guard.

“Then your light will break out like the dawn,And your recovery will speedily spring forth;And your righteousness will go before you;The glory of the Lord will be your rear guard.

“But I will remove the northern army far from you,And I will drive it into a parched and desolate land,And its vanguard into the eastern sea,And its rear guard into the western sea.And its stench will arise and its foul smell will come up,For it has done great things.”