1 Samuel 17:47

And all this assembly shall know,.... The congregation of Israel, and church of the living God, great part of which were now gathered together, and were spectators of this wonderful event:

that the Lord saveth not with sword and spear; that is, by outward means and instruments, by arms and armed men; he does not save by them only, or by them always; he can save as well without them as with them:

for the battle [is] the Lord's; it is under his direction; the issue and event of it depend on his will, and are owing to him; or, as the Targum,

"from the Lord is the victory of wars,''

it is he that gives it to whom he pleases:

and he will give you into our hands; not only this Philistine into the hands of David, but the army of them into the hands of the Israelites; David knew, and was assured of this by the Lord, and it was on this he relied, and was what animated him to engage with this champion in the manner he did.