2 Samuel 3:32

So Joab, and Abishai his brother slew Abner, because he had slain their brother Asahel at Gibeon in the battle.

And David said to Joab, and to all the people that were with him, Rend your clothes, and gird you with sackcloth, and mourn before Abner. And king David himself followed the bier.

And the king lamented over Abner, and said, Died Abner as a fool dieth?

Thy hands were not bound, nor thy feet put into fetters: as a man falleth before wicked men, so fellest thou. And all the people wept again over him.