1 Samuel 16:13

Anointed him in the midst of his brethren. — The history here simply relates the bare fact that the young shepherd was anointed in the presence of his brethren. No words of Samuel on this occasion are recorded; we are left, therefore, uncertain whether any reason was given for the choice of David, or any explanation of this peculiar anointing. It would seem most probable that Samuel kept silence for the present respecting the high destinies of the boy standing before him, and that he merely anointed him as one chosen to be his assistant in the sacrifice he was about to offer, stating probably that the Spirit of the Lord had directed him thus to associate the young son of Jesse with himself, and to adopt him in some way as a pupil in his prophetic school. From this time forward much of David’s time was doubtless spent in Samuel’s company. From him he received his training in poetry and music, for which he subsequently became distinguished; from the wise seer, too, the future king derived those early lessons of wisdom and learning which enabled him later to fill so nobly the great position for which he was thus early marked out. David was, before everything, Samuel’s pupil, and the last years of that long and memorable career of the prophet were spent in moulding the life of Israel’s greatest king.

And the Spirit of the Lord came upon David... (14) But the Spirit of the Lord departed from Saul. — This “Spirit of the Lord” which on the day of his anointing by Samuel came upon the shepherd boy, was the “Holy Ghost, or good Spirit of God,” and is clearly and formally opposed to those evil spirits which (to use the words of Bishop Pearson) “must be acknowledged persons of a spiritual and intellectual subsistence, as the Spirit of the Lord departed from Saul, and an evil spirit from the Lord troubled him. Now, what those evil spirits from the Lord were is apparent from the sad example of Ahab, concerning whom we read, There came out a spirit and stood before the Lord, and said, I will entice him; and the Lord said unto him, Wherewith? and he said, I will go out, and be a lying spirit in the mouth of all his prophets. And the Lord said, Thou shalt entice him, and thou shalt also prevail; go out, and do even so. From whence it is evident that the evil spirits from God were certain persons — even bad angels — to which the one good Spirit as a person is opposed, departing from him to whom the other cometh” (Bishop Pearson, Creed, Art. 8).

The effect of this descent of the Spirit of the Lord upon David was that the shepherd boy grew up into a hero, a statesman, a scholar, and a wise, far-sighted king. The effect of the departure of the Spirit from Saul was that from that hour the once generous king became a prey to a groomy melancholy, and a victim to a torturing jealousy of others, which increased as time went on, and which goaded him now and again to madness, ruining his life, and marring utterly the fair promise of his early years.