Charles Ellicott Commentary Psalms 30:9

"What profit is there in my blood, when I go down to the pit? Shall the dust praise thee? shall it declare thy truth?" — Psalms 30:9 (ASV)

What profit ... — that is, to God. For the conception of death as breaking the covenant relation between Israel and Jehovah, and so causing loss to Him as well as to them (for Sheôl had its own king or shepherd, Death) by putting an end to all religious service, compare Hezekiah’s song (Isaiah 38:18). Compare also Psalms 6:5, and note Psalms 88:11.

Plainly, no hope had yet arisen, not even a dim one, of praising God beyond the grave. The vision of the New Jerusalem, with the countless throngs of redeemed with harps and palms, was still in the future.