The person who is praying, David, complains to the Lord because of the shameful behaviour of his enemy, Cush, the Benjaminite. Cush may be translated as the Ethiopian. Whom it concerns here cannot be said with certainty. Perhaps it was about someone who was close to Saul—from Benjamin. It is possible that this is a story that was verbally passed on.
The poet is in dire need. That tone is clear throughout the Psalm. He takes refuge in the Lord, from the enemy which he calls a lion which tears apart. Compare this with Psalm 58:6, where the poet asks the Lord to tear out the fangs of the young lions. The place of refuge (Psalm 7:1) can literally be the house of God, the holy place. But God (himself) as place of refuge is also very fitting.
1 O LORD my God, in you do I take refuge; save me from all my pursuers and deliver me,