David
Psalm 89:15ESV·traditional attribution

Blessed are the people who know the festal shout, who walk, O LORD, in the light of your face,

John Calvin Reformed @genevareformer

PSALM 89 The prophet who wrote this psalm, whoever he was, in approaching the throne of grace to make supplication to God in behalf of the afflicted Church, lays down, as an encouragement both to himself and the rest of the faithful to cherish good hope, the covenant which God had made with David.

Commenting on Psalm 89:1-52

C.H. Spurgeon Reformed Baptist @princeofpreachers

Blessed is the people that know the joyful sound. It is a blessed God of whom the Psalmist has been singing, and therefore they are a blessed people who partake of his bounty, and know how to exult in his favour. Praise is a peculiarly joyful sound, and blessed are those who are familiar with its strains.

Matthew Henry Presbyterian @wholebiblehenry

The psalmist, having largely shown the blessedness of the God of Israel, here shows the blessedness of the Israel of God. As there is none like unto the God of Jeshurun, so, happy art thou, O Israel! there is none like unto thee, O people! especially as a type of the gospel-Israel, consisting of all true believers, whose happiness is here described. I.

Commenting on Psalm 89:15-18