(33) And Saul said to David . . .--The king evidently looked on the brave boy with love and admiration, but at first doubted in his heart the reality of David's mission. Whether or not Saul recognised the youth as the sweet singer who had charmed away, perhaps more than once, that terrible soul malady of his which was desolating his once vigorous manhood, is doubtful. (See the Note at the end of this chapter.) He--more than any one in that armed camp--evidently felt that David possessed powers not usually bestowed on the sons of men, and was clearly disposed from the first to grant the shepherd boy's startling petition that the honour of Israel might be entrusted to his almost child-hands. Still, Saul would talk with him, and set before him the grave perils of the terrible encounter he was so eager to engage in.

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.And Saul said to David, thou art not able to go against this Philistine to fight with him,.... Had neither strength of body, nor skill in military affairs, to encounter with a man of his stature, and warlike genius and practice:

for thou art but a youth; some say about fourteen or sixteen years of age, but very probably about twenty, and not more, and so not only weak, but inexpert in the art of fighting:

and he a man of war from his youth; a gigantic man, trained up in, inured to, and expert in the affairs of war; so that David could not, on any account, be a competitor with him, and a match for him.