28 When Eliab, David's oldest brother, heard him speaking with the men, he burned with anger at him and asked, "Why have you come down here? And with whom did you leave those few sheep in the wilderness? I know how conceited you are and how wicked your heart is; you came down only to watch the battle."

Matthew Henry's Commentary on 1 Samuel 17:28

Commentary on 1 Samuel 17:12-30

(Read 1 Samuel 17:12-30)

Jesse little thought of sending his son to the army at that critical juncture; but the wise God orders actions and affairs, so as to serve his designs. In times of general formality and lukewarmness, every degree of zeal which implies readiness to go further, or to venture more in the cause of God than others, will be blamed as pride and ambition, and by none more than by near relations, like Eliab, or negligent superiors. It was a trial of David's meekness, patience, and constancy. He had right and reason on his side, and did not render railing for railing; with a soft answer he turned away his brother's wrath. This conquest of his own passion was more honourable than that of Goliath. Those who undertake great and public services, must not think it strange if they are spoken ill of, and opposed by those from whom they expect support and assistance. They must humbly go on with their work, in the face not only of enemies' threats, but of friends' slights and suspicions.