These first chapters of 2 Samuel show a great model of what it means to love your enemies and pray for those who persecute you.
This is the start of David’s lament for Saul when he hears of his death. He is mourning his friend, Jonathan, too, but there is no sense that he is just doing his duty by Saul and really mourning Jonathan. In fact, most people would expect him to make some comment to the effect that Saul had got his just deserts, but in word and deed David’s response suggests only that a great, worthy and much loved king has died.
What an incredible example.