The LORD your God, who goes before you, will fight for you, just as you saw Him do for you in Egypt
Moses here makes a large rehearsal of the fatal turn which was given to their affairs by their own sins, and God's wrath, when, from the very borders of Canaan, the honour of conquering it, and the pleasure of possessing it, the whole generation was hurried back into the wilderness, and their carcases fell there. It was a memorable story; we read it Num.
Commenting on Deuteronomy 1:19-46
The LORD your God which goeth before you, he shall fight for you, according to all that he did for you in Egypt before your eyes; (s) Declaring that to renounce our own force, and constantly to follow our calling, and depend on the Lord, is true boldness, and agreeable to God.
Deu 1:29-31 The attempt made by Moses to inspire the despondent people with courage, when they were ready to despair of ever conquering the Canaanites, by pointing them to the help of the Lord, which they had experienced in so mighty and visible a manner in Egypt and the desert, and to urge them to renewed confidence in this their almighty Helper and Guide, was altogether without success.
Commenting on Deuteronomy 1:29-31