Nor sword nor spear the stripling took, / But chose a pebble from the brook.

The sword of him that layeth at him cannot hold: the spear, the dart, nor the habergeon.

A cheap but wholesome salad from the brook.

And he took his staff in his hand, and chose him five smooth stones out of the brook, and put them in a shepherd's bag which he had, even in a scrip; and his sling was in his hand: and he drew near to the Philistine.

The pebble in the brook secretly thinks itself a precious stone

Then said David to the Philistine, Thou comest to me with a sword, and with a spear, and with a shield: but I come to thee in the name of the LORD of hosts, the God of the armies of Israel, whom thou hast defied.