David
Psalm 40:14BSB·traditional attribution

May those who seek my life be ashamed and confounded; may those who wish me harm be repelled and humiliated.

John Calvin Reformed @genevareformer

PSALM 40 David, being delivered from some great danger, and it may be, not from one only, but from many, extols very highly the grace of God, and by means of this, his soul is filled with admiration of the providence of God, which extends itself to the whole human race.

Commenting on Psalm 40:1-17

C.H. Spurgeon Reformed Baptist @princeofpreachers

Let them be ashamed and confounded together that seek after my soul to destroy it. Whether we read this as a prayer or a prophecy it matters not, for the powers of sin, and death, and hell, may well be ashamed as they see the result of their malice for ever turned against themselves.

Matthew Henry Presbyterian @wholebiblehenry

The psalmist, having meditated upon the work of redemption, and spoken of it in the person of the Messiah, now comes to make improvement of the doctrine of his mediation between us and God, and therefore speaks in his own person.

Commenting on Psalm 40:11-17