12 And David 'is' son of this Ephrathite of Beth-Lehem-Judah, whose name 'is' Jesse, and he hath eight sons, and the man in the days of Saul hath become aged among men; 13 and the three eldest sons of Jesse go, they have gone after Saul to battle; and the name of his three sons who have gone into battle 'are' Eliab the first-born, and his second Abinadab, and the third Shammah. 14 And David is the youngest, and the three eldest have gone after Saul, 15 and David is going and returning from Saul, to feed the flock of his father at Beth-Lehem.

Matthew Henry's Commentary on 1 Samuel 17:12-15

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.