Matthew Henry Commentary 1 Samuel 17:31-39

"And when the words were heard which David spake, they rehearsed them before Saul; and he sent for him. And David said to Saul, Let no man`s heart fail because of him; thy servant will go and fight with this Philistine. And Saul said to David, Thou art not able to go against this Philistine to fight with him; for thou art but a youth, and he a man of war from his youth. And David said unto Saul, Thy servant was keeping his father`s sheep; and when there came a lion, or a bear, and took a lamb out of the flock, I went out after him, and smote him, and delivered it out of his mouth; and when he arose against me, I caught him by his beard, and smote him, and slew him. Thy servant smote both the lion and the bear: and this uncircumcised Philistine shall be as one of them, seeing he hath defied the armies of the living God. And David said, Jehovah that 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 unto David, Go, and Jehovah shall be with thee. And Saul clad David with his apparel, and he put a helmet of brass upon his head, and he clad him with a coat of mail. And David girded his sword upon his apparel, and he assayed to go; for he had not proved it. And David said unto Saul, I cannot go with these; for I have not proved them. And David put them off him." — 1 Samuel 17:31-39 (ASV)

A shepherd lad, who had come that 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 anger with meekness, so David answered Saul's fear with faith. When David kept sheep, he proved himself very careful and tender toward his flock.

This reminds us of Christ, the Good Shepherd, who not only ventured but laid down his life for the sheep. Our experience should encourage us to trust in God and be bold in the way of duty. He who has delivered, does deliver, and will continue to do so. David received permission to fight the Philistine.

Not being used to the kind of armor Saul put on him, he was not content to go in that manner. This was from the Lord, so that it might more plainly appear that he fought and conquered in faith, and that the victory was from Him who works by the feeblest and most despised means and instruments. We should not inquire how excellent anything is, but how appropriate it is. Let Saul's coat be ever so rich, and his armor ever so strong, what good is it to David if they do not fit him?

But faith, prayer, truth, and righteousness; the whole armor of God, and the mind that was in Christ; are equally necessary for all the servants of the Lord, whatever their work may be.