Psalm 59:10 (ESV)

10 My God in his steadfast love will meet me; God will let me look in triumph on my enemies.

The author says that his God will take care of him because of God’s faithful love. He will help the author in such a way, that he can look down upon his enemies—just as God pictures it in Psalm 59:8 laugh at them and nations in derision. Thus, the roles have been perfectly reversed: first pleading for help against the enemies, and now looking down upon those enemies.