But as for me, I will walk in mine integrity: redeem me, and be merciful unto me.
Walk in mine integrity - resuming the theme, Psalms 26:1. His rectitude stands in contrast to the "mischief" and "bribes" of the "sinners" (Psalms 26:9-10).
Redeem ... merciful. Prayer for redemption and mercy must be offered with a sincere desire to act in "integrity," or else it is rejected.