34 And David said to Saul, Thy servant fed his father's sheep, and there came a lion, and also a bear, and took a lamb out of the flock. 35 And I went after him, and smote him, and delivered it out of his mouth; and when he arose against me, I seized him by his beard, and smote him, and slew him. 36 Thy servant smote both the lion and the bear; and this uncircumcised Philistine shall be as one of them, because he has defied the armies of the living God. 37 And David said, Jehovah who delivered me out of the paw of the lion and out of the paw of the bear, he will deliver me out of the hand of this Philistine. And Saul said to David, Go, and Jehovah be with thee.

Matthew Henry's Commentary on 1 Samuel 17:34-37

Commentary on 1 Samuel 17:31-39

(Read 1 Samuel 17:31-39)

A shepherd lad, come the same morning from keeping sheep, had more courage than all the mighty men of Israel. Thus God often sends good words to his Israel, and does great things for them, by the weak and foolish things of the world. As he had answered his brother's passion with meekness, so David answered Saul's fear with faith. When David kept sheep, he proved himself very careful and tender of his flock. This reminds us of Christ, the good Shepherd, who not only ventured, but laid down his life for the sheep. Our experience ought to encourage us to trust in God, and be bold in the way of duty. He that has delivered, does and will continue to do so. David gained leave to fight the Philistine. Not being used to such armour as Saul put upon him, he was not satisfied to go in that manner; this was from the Lord, that it might more plainly appear he fought and conquered in faith, and that the victory was from Him who works by the feeblest and most despised means and instruments. It is not to be inquired how excellent any thing is, but how proper. Let Saul's coat be ever so rich, and his armour ever so strong, what is David the better if they fit him not? But faith, prayer, truth, and righteousness; the whole armour of God, and the mind that was in Christ; are equally needful for all the servants of the Lord, whatever may be their work.