John Gill Commentary Psalms 26:11

"But as for me, I will walk in mine integrity: Redeem me, and be merciful unto me." — Psalms 26:11 (ASV)

But as for me, I will walk in my integrity
In which he had walked until now, (Psalms 26:1); or it may express his faith, that after he was gathered by death he should walk in uprightness and righteousness, in purity and perfection, with Christ in white, and behold the face of God in righteousness; see (Isaiah 57:1Isaiah 57:2);

redeem me ;
from the vain conversation of the wicked, from all troubles, and out of the hands of all enemies;

and be merciful unto me ;
who was then in distress, being persecuted by Saul, and at a distance from the house of God: this shows that mercy is the source and spring of redemption, both temporal and spiritual; and that the psalmist did not trust in and depend upon his present upright walk and conversation, but in redemption by Christ, and upon the mercy of God in Christ.