But Amasa took no heed to the sword that was in Joab's hand: so he struck him with it in the fifth rib, and shed out his entrails to the ground, and struck him not again; and he died. So Joab and Abishai his brother pursued after Sheba the son of Bichri.
All Commentaries on 2 Samuel 20:10 Go To 2 Samuel 20
Gregory The Dialogist
AD 604
Thus also the wicked, because they have evil not upon the tongue but under the tongue, in the words of their mouth they hold out sweet things, and in the thoughts of their heart are plotting mischief. For it is hence that Joab held the beard of Amasa with his right hand, while secretly putting his left hand to his sword, he spilled out his bowels. For to hold the chin with the right hand is to caress as if in kindness. But he puts his left hand to his sword, who in secret strikes in malice.