for the LORD your God is he who goes with you to fight for you against your enemies, to give you the victory.’
Israel was at this time to be considered rather as a camp than as a kingdom, entering upon an enemy's country, and not yet settled in a country of their own; and, besides the war they were now entering upon in order to their settlement, even after their settlement they could neither protect nor enlarge their coast without hearing the alarms of war.
Commenting on Deuteronomy 20:1-9
For the Lord your God is he that goeth with you,.... To battle, and therefore they had no reason to fear and be dismayed, to be fainthearted, terrified, and tremble: fear not, I am with thee,.... Isa 41:10, this, according to the Misnah (f), respects the ark, and so Jarchi, which was a symbol of the divine Presence, and went with them to battle; see Jos 6:4.
your God is he that goeth with you, to fight for you against your enemies, to save you--According to Jewish writers, the ark was always taken into the field of combat. But there is no evidence of this in the sacred history; and it must have been a sufficient ground of encouragement to be assured that God was on their side.