John Wesley on Deuteronomy 33:29

The shield of they help - By whom thou are sufficiently guarded against all assailants; and the sword of thy excellency - Or, thy most excellent sword, that is, thy strength and the author of all thy past or approaching victories. Those in whose hearts is the excellency of holiness, have God himself for their shield and sword. They are defended by the whole armour of God: His word is their sword, and faith their shield. And thine enemies shall be found liars unto thee - Who said they would destroy thee: or at least, that they would never submit: and thou shalt tread upon their high places - Their strong holds, palaces and temples. Thus shall the God of peace tread Satan under the feet of all believers, and that shortly.