John Gill Commentary 1 Samuel 17:24

"And all the men of Israel, when they saw the man, fled from him, and were sore afraid." — 1 Samuel 17:24 (ASV)

And all the men of Israel, when they saw the man
Even as it should seem before they heard him; knowing who he was, and what he was about to say, having seen and heard him forty days running:

fled from him, and were sore afraid;
it is pretty much a whole army should be afraid of one man, and flee from him; they must be greatly forsaken of God, and given up by him, see (Deuteronomy 32:30); but perhaps they were not so much afraid of personal danger from him, as that they could not bear to hear his blasphemy.