Rereward

Rereward (an archaic form of rearguard) is used in the KJV for the rear or covering force of a marching army or procession. In Numbers 10:25, the tribe of Dan served as the rereward for the entire camp of Israel in the wilderness march — the last tribal contingent, gathering and protecting the stragglers. Isaiah 52:12 and 58:8 use the image theologically: God promises his people that in the new Exodus from Babylon they will not leave in haste as they did from Egypt, for the God of Israel will be your rereward — protecting the rear of the procession. The image conveys complete divine protection from before and behind simultaneously.