David
Psalm 88:1ESV·traditional attribution

O LORD, God of my salvation, I cry out day and night before you.

John Calvin Reformed @genevareformer

PSALM 88 This psalm contains very grievous lamentations, poured forth by its inspired penman when under very severe affliction, and almost at the point of despair. But he, at the same time, whilst struggling with sorrow, declares the invincible steadfastness of his faith; which he displayed in calling upon God to deliver him, even when he was in the, deep darkness of death.

Commenting on Psalm 88:1-18

C.H. Spurgeon Reformed Baptist @princeofpreachers

O Lord God of my salvation. This is a hopeful title by which to address the Lord, and it has about it the only ray of comfortable light which shines throughout the Psalm. The writer has salvation, he is sure of that, and God is the sole author of it. While a man can see God as his Saviour, it is not altogether midnight with him.

Matthew Henry Presbyterian @wholebiblehenry

It should seem, by the titles of this and the following psalm, that Heman was the penman of the one and Ethan of the other. There were two, of these names, who were sons of Zerah the son of Judah, Ch1 2:4, Ch1 2:6. There were two others famed for wisdom, Kg1 4:31, where, to magnify Solomon's wisdom, he is said to be wiser than Heman and Ethan.

Commenting on Psalm 88:1-9