What does 1 Samuel 17:48 mean?

The Philistines and Israelites have been encamped against one another for war (1 Samuel 17:1–3). For forty days, a Philistine giant, Goliath, has been challenging Israel to representative champion warfare (1 Samuel 17:4–10, 16). Such a duel seems unwinnable, and Israel has responded with fear (1 Samuel 17:11, 24). But David, having heard the Philistine's taunts while checking on his older brothers at the battle (1 Samuel 17:12–18), has volunteered (1 Samuel 17:32). King Saul has agreed to send the youth, clad only in shepherd's gear (1 Samuel 17:40). David is confident the Lord will deliver him (1 Samuel 17:37).

After Goliath's curses and insults (1 Samuel 17:42–44) come David's confident declarations that the Lord would give the victory (1 Samuel 17:45–47).Now the battle between the giant warrior and the inexperienced youth begins. Goliath starts toward David, but the text seems to indicate that his approach is slow. He is said to rise and come and draw near to David, needing three verbs to describe his movement. Perhaps the giant man is weighed down by heavy armor and weapons or is simply being cautious—or bored. He is also moving behind his shield-bearer. In any case, Goliath closes distance to the youthful David.

David, on the other hand, is simply said to have run toward the battle line to meet Goliath. Without anything heavy to slow him down, David was free to quickly run straight toward his enemy, preparing to fire his sling when he was within good range. This might have been part of David's strategy: to add even more power to his first slung stone.