What does 1 Samuel 17:28 mean?
The Philistines and Israelites are encamped against one another for war at the Valley of Elah (1 Samuel 17:1–3, 19). An imposing Philistine champion, Goliath (1 Samuel 17:4–7), has challenged the Israelites to a duel (1 Samuel 17:8–10, 16, 23). If an Israelite could kill Goliath, the Philistines would become Israel's servants. If Goliath prevailed, Israel would surrender. The entire army of Israel responds to this seemingly insurmountable threat in fear (1 Samuel 17:11, 24). The men also speak of the reward that would be given to any Israelite able to conquer their foe: great riches, becoming son-in-law of King Saul, and that his family would be relieved of compulsory civic duty.David's three oldest brothers are at the battlefield (1 Samuel 17:12–15). David has come from watching the family's sheep at Bethlehem to deliver a gift of food and check on them (1 Samuel 17:17–18). All, including David, have heard Goliath's threat (1 Samuel 17:23). David has asked about the situation, noting that it was embarrassing for a pagan to continually insult the living God (1 Samuel 17:26–27).
In asking this question, David highlights the shame of Israel as well as his confidence in God. The Philistines are no match for the God of Israel, so who will take the challenge? David's oldest brother, Eliab, is probably at least ten years older than David. When young David shows up with his youthful enthusiasm, eagerness, and confidence, Eliab takes offense. What Eliab seems to hear is his youngest brother challenging his courage and manhood—even his faith and that of the warriors of Israel.
Eliab is furious at his little brother. He asks David why he has even come to the battle and who is watching his little flock of sheep, trying to show how small and insignificant David truly is. Eliab then describes David's heart as presumptuous and evil, claiming he has only come to see the excitement of the battle. Older brothers often see it as their role to take their younger siblings down a notch or two, but Eliab's resentment seems to run even deeper than that.