2 Samuel 20:7-11

And there went out after him Joab’s men, and the Cherethites, and the Pelethites, and all the mighty men: and they went out of Jerusalem, to pursue after Sheba the son of Bichri.

When they were at the great stone which is in Gibeon, Amasa went before them. And Joab’s garment that he had put on was girded unto him, and upon it a girdle with a sword fastened upon his loins in the sheath thereof; and as he went forth it fell out.

And Joab said to Amasa, Art thou in health, my brother? And Joab took Amasa by the beard with the right hand to kiss him.

But Amasa took no heed to the sword that was in Joab’s hand: so he smote him therewith in the fifth rib, and shed out his bowels to the ground, and struck him not again; and he died. So Joab and Abishai his brother pursued after Sheba the son of Bichri.

And one of Joab’s men stood by him, and said, He that favoureth Joab, and he that is for David, let him go after Joab.