2 Samuel 1:13-15

Then David said to the young man who had brought the news, “Where are you from?” And he replied, “I am a foreigner, an Amalekite, who lives in your land.” “Why were you not afraid to kill the LORD’s anointed one?” David asked. Then David said to one of his men, “Kill him!” So the man thrust his sword into the Amalekite and killed him.