What does Psalm 35:13 mean?

In sadness (Psalm 35:11–12), David reflects on the compassionate treatment he showed his foes before they turned against him. He does not identify them, but it's likely these were people aligned with either Saul (1 Samuel 19:1–2) or Absalom (2 Samuel 15:13–14). They may have been members of the court or soldiers in the army. David had served in both, prior to becoming king. Whoever they were, David had shown personal concern for them. He followed the typical process of mourning; he fasted and prayed for them. He was a devoted friend to those individuals. Yet they turned on him and even sought his death.

Again, David's actions prefigure those of Jesus. Jesus "went about doing good and healing all who were oppressed by the devil, for God was with him" (Acts 10:38). Jesus opened His arms to the children, healed the deaf and the blind, cleansed lepers, and raised the dead, never doing harm to anyone. Yet His lifestyle of consistent kindness was met with clamors for His death (Mark 15:13). At Pentecost, Peter told the crowd of Jews that Jesus was crucified and killed by the hands of lawless men (Acts 2:23).