And David put his hand in his bag
The shepherd's scrip, in which he had put the five stones he took out of the brook:
and took thence a stone;
and put it into his sling he had in his hand:
and slang [it], and smote the Philistine in his forehead;
it is made a difficulty of how he should smite him on his forehead, when he had a helmet of brass upon his head, ( 1 Samuel 17:5 ) ; in answer to this Kimchi observes, that some say, that when David said he would give his flesh to the fowls of the air, at the mention of that he looked upwards, and what was upon his forehead fell backwards, and then David slung and smote him; or he might put back his helmet to talk with David, and hear and be heard the better; and having nothing to fear from an unarmed man, might neglect to put it forward again; or there might be some open space left in the helmet for him to look through, in at which the stone might pass; so the Targum renders it, he smote him in the house of his eyes, so the stone passed through the eye hole into his brain: but after all, supposing his forehead ever so well covered, as the stone slung by David was under a divine direction, so as to hit a person in motion, it came with a divine power, which nothing could resist; and supposing this, of which there need no doubt, it could as easily pass through the helmet of brass, as pierce into his forehead and sink there; nor can this be thought the least incredible, if what Diodorus Siculus F13 relates of the Baleares be true, that they were so dexterous at slinging, that they not only would sling stones bigger than others could, and were so directed, that they seldom missed their mark, being inured to it from their youth, but would even in battle break in pieces shields, helmets, and all kinds of armour, with which bodies were covered:
that the stone sunk into his forehead;
and so into his brain, as a stone is immersed and sinks in water, when thrown into it; with such force did it go, and with so much ease did it make its way, through the direction and power of God:
and he fell upon his face to the earth;
Jarchi observes, that it was most natural for him to have fallen backwards, being struck upon his forehead; but so it was, that David might have no trouble to cut off his head, for by this means he fell nearer to him.