John Gill's Exposition of the Whole Bible
Psalms 78:70
He chose David also his servant,.... To be king of Israel, the youngest of his father's family, when he rejected all the rest; see
1 Samuel 16:6, an eminent type of our Lord Jesus Christ, who is called by his name, Psalms 89:3 and the signification of his name "Beloved" agrees with him, who is beloved of God, as his Son, and as man and Mediator; and beloved of men, of all the saints: and so likewise his character as a servant suits with him; who not only frequently has the name of a servant, Psalms 89:19, but appeared in the form of one, Philippians 2:7, had the work of a servant to do, which he has accomplished, even the great work of our salvation,
John 17:4, in doing which, and all things leading on and appertaining to it, he took the utmost delight and pleasure, and used the greatest diligence and assiduity, John 4:34 and justly acquired the character of a faithful and righteous servant, Isaiah 53:11, and to this work and office he was chosen and called by his Father,
and took him from the sheepfolds; from whence he was fetched when Samuel was sent by the Lord to anoint him, 1 Samuel 16:11, so Moses, while he was feeding his father's sheep, was called to be the saviour and deliverer of Israel, Exodus 3:1, and Amos was taken from following the flock to be a prophet of the Lord, Amos 7:13, and as David was a type of Christ, this may express the mean condition of our Lord, in his state of humiliation, previous to his exaltation, and the more open exercise of his kingly office.