2 Samuel 3:28-31

28Afterward, when David heard of it, he said, “I and my kingdom are forever innocent before the Lord of the blood of Abner the son of Ner.

29Let the guilt fall on the head of Joab and on all his father’s house (family); and may there never disappear from the house of Joab one who suffers with a discharge or one who is a leper or one who walks with a crutch [being unfit for war], or one who falls by the sword, or one who lacks food.”

30So Joab and Abishai his brother murdered Abner because he had killed their brother Asahel in the battle at Gibeon.

31Then David said to Joab and to all the people with him, “Tear your clothes, put on sackcloth, and mourn before Abner.” And King David walked behind the bier.