David
Psalm 78:70ESV·traditional attribution

He chose David his servant and took him from the sheepfolds;

John Calvin Reformed @genevareformer

PSALM 78 To comprehend many things within small compass, it is to be observed, that in this psalm there are two leading topics. On the one hand, it is declared how God adopted for himself a Church from the posterity of Abraham, how tenderly and graciously he cherished it, how wonderfully he brought it out of Egypt, and how varied were the blessings which he bestowed upon it.

Commenting on Psalm 78:1-72

C.H. Spurgeon Reformed Baptist @princeofpreachers

He chose David also his servant. It was an election of a sovereignly gracious kind, and it operated practically by making the chosen man a willing servant of the Lord. He was not chosen because he was a servant, but in order that he might be so. David always esteemed it to be a high honour that he was both elect of God, and a servant of God.

Matthew Henry Presbyterian @wholebiblehenry

The matter and scope of this paragraph are the same with the former, showing what great mercies God had bestowed upon Israel, how provoking they had been, what judgments he had brought upon them for their sins, and yet how, in judgment, he remembered mercy at last.

Commenting on Psalm 78:40-72