2 Samuel 3:27-30

27When Abner returned to Hebron, Joab pulled him aside to the middle of the city gate, as if to speak to him privately, and there Joab stabbed him in the stomach. So Abner died in revenge for the death of Asahel, Joab’s brother.

28David heard about it later and said, “I and my kingdom are forever innocent before the Lord concerning the blood of Abner son of Ner.

29May it hang over Joab’s head and his father’s whole family, and may the house of Joab never be without someone who has a discharge or a skin disease, or a man who can only work a spindle, or someone who falls by the sword or starves.”

30Joab and his brother Abishai killed Abner because he had put their brother Asahel to death in the battle at Gibeon.