What does 1 Samuel 17:35 mean?
Encamped at the Valley of Elah against the Philistines, the Israelite army has yet to produce a champion. A Philistine giant, Goliath, has been taunting them for forty days, challenging Israel to send a man to fight him (1 Samuel 17:16). The winner of that battle would be the representative victor for his nation (1 Samuel 17:8–10). But Goliath is no ordinary man. He is half-again as tall as the other soldiers, dressed in full protective gear, and equipped with the latest in weapon technology (1 Samuel 17:4–7).David has come to the battlefield to deliver food to his brothers (1 Samuel 17:17–18). Hearing the Philistine's challenge, David asks what will be done for the Israelite who removes this shame (1 Samuel 17:26). David indicates Goliath has no standing against the armies of the living God. David's words are reported to King Saul, who calls the young man (1 Samuel 17:31). David volunteers to fight Goliath (1 Samuel 17:32).
Evidently, David isn't old enough to serve in the military, so Saul says the boy is no match for a seasoned warrior like Goliath. David responds with his resume as a shepherd (1 Samuel 17:34). Attacks by wild animals were apparently a normal part of shepherding a flock of sheep during this era. Lions and bears did indeed roam the forest and hills of Israel, looking for prey. A flock of sheep guarded by a boy likely made for an inviting target.
David's point to King Saul was that he was not just any boy-shepherd. He did not allow lions and bears to make off with his sheep for the sake of his own safety. Instead, when a large predator would attack his flock and take a sheep, David would chase the animal down. He would hit the beast, likely with his staff, to save the sheep out of its mouth. If the lion or bear turned to attack David, the boy would continue to strike it until it was dead, even grabbing it by the hair of its jaw or neck if necessary.
David wants the king to understand that his courage to fight Goliath isn't just youthful boldness. He believes himself to be experienced in battle against much larger opponents that wanted to kill him.