2 Samuel 1:12-16

And they mourned and wept and fasted until evening for Saul and his son Jonathan, and for the people of the Lord and the house of Israel, because they had fallen by the sword.

Then David said to the young man who informed him, “Where are you from?” And he answered, “I am the son of a stranger, an Amalekite.”

And David said to him, “How is it you were not afraid to reach out with your hand to destroy the Lord’s anointed?”

Then David called one of the young men and said, “Come forward, put him to death.” So he struck him and he died.

And David said to him, “Your blood is on your head, because your own mouth has testified against you, saying, ‘I have finished off the Lord’s anointed.’ ” David’s Song of Mourning for Saul and Jonathan