'Rear guard' in the Bible

The seven priests bearing 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. The rear guard came after the ark of the LORD. The trumpets sounded as they went.

For you shall not depart in haste, nor shall you leave in flight; for the LORD will go before you, and the God of Israel will be your rear guard.

Then your light shall break forth as the morning, and your healing shall spring forth speedily; and your righteousness shall go before you; the glory of the LORD shall be your rear guard.