'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, moved out, with Ahiezer the son of Ammishaddai [commander] over its army,

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

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

For you will not go out in a hurry [as when you left Egypt],Nor will you go in flight [fleeing, as you did from the Egyptians];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 healing (restoration, new life) will quickly spring forth;Your righteousness will go before you [leading you to peace and prosperity],The glory of the Lord will be your rear guard.