Passage
And David put his hand in his bag, and took thence a stone, and slang it, and smote the Philistine in his forehead, that the stone sunk into his forehead; and he fell upon his face to the earth.
And David put his hand in his bag, and took thence a stone, and slang it, and smote the Philistine in his forehead, that the stone sunk into his forehead; and he fell upon his face to the earth.
1 Samuel 17:47 And all this assembly shall know that the LORD saveth not with sword and spear: for the battle is the LORD’s, and he will give you into our hands.
1 Samuel 17:48 And it came to pass, when the Philistine arose, and came, and drew nigh to meet David, that David hastened, and ran toward the army to meet the Philistine.
1 Samuel 17:49 And David put his hand in his bag, and took thence a stone, and slang it, and smote the Philistine in his forehead, that the stone sunk into his forehead; and he fell upon his face to the earth.
1 Samuel 17:50 So David prevailed over the Philistine with a sling and with a stone, and smote the Philistine, and slew him; but there was no sword in the hand of David.
1 Samuel 17:51 Therefore David ran, and stood upon the Philistine, and took his sword, and drew it out of the sheath thereof, and slew him, and cut off his head therewith. And when the Philistines saw their champion was dead, they fled.
The verse centers on "david", "hand", "took", "thence", "stone", "slang", "smote", and "philistine". It is saying that the verse draws attention to "david" and "hand", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 48's "And it came to pass when the..." into verse 50's "So David prevailed over the Philistine with...", so "david" and "hand" belong inside that flow. In 1 Samuel context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "david" and "hand" with trust shaped by these words, not by a vague optimism outside the passage.