20 And David got up early in the morning, and, giving the sheep into the care of a keeper, took the things and went as Jesse had said; and he came to the lines where the carts were, when the army was going out to the fight giving their war-cry. 21 And Israel and the Philistines had put their forces in position, army against army. 22 And David gave his parcels into the hands of the keeper of the army stores, and went running to the army and came to his brothers to get knowledge about them. 23 And while he was talking to them, the fighter, the Philistine of Gath, Goliath by name, came out from the Philistines' lines and said the same words, in David's hearing. 24 And all the men of Israel, when they saw him, went in flight, overcome with fear. 25 And the men of Israel said, Have you seen this man? Clearly he has come out to put shame on Israel: and it is certain that if any man overcomes him, the king will give that man great wealth, and will give him his daughter, and make his father's family free in Israel. 26 And David said to the men near him, What will be done to the man who overcomes this Philistine and takes away the shame from Israel? for who is this Philistine, a man without circumcision, that he has put shame on the armies of the living God?

Matthew Henry's Commentary on 1 Samuel 17:20-26

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.