5 So Amasa went to call out the men of Judah , but he delayed longer than the set time which he had appointed him. 6 And David said to Abishai , "Now Sheba the son of Bichri will do us more harm than Absalom ; take your lord's servants and pursue him, so that he does not find for himself fortified cities and escape from our sight ." 7 So Joab's men went out after him, along with the Cherethites and the Pelethites and all the mighty men ; and they went out from Jerusalem to pursue Sheba the son of Bichri . 8 When they were at the large stone which is in Gibeon , Amasa came to meet them. Now Joab was dressed e in his military attire e , and over it was a belt with a sword in its sheath fastened at his waist ; and as he went forward , it fell out. 9 Joab said to Amasa , "Is it well with you, my brother ?" And Joab took Amasa by the beard with his right hand to kiss him. 10 But Amasa was not on guard against the sword which was in Joab's hand so he struck him in the belly with it and poured out his inward parts on the ground , and did not strike him again , and he died . Then Joab and Abishai his brother pursued Sheba the son of Bichri .
Matthew Henry's Commentary on 2 Samuel 20:5-10
Commentary on 2 Samuel 20:4-13
(Read 2 Samuel 20:4-13)
Joab barbarously murdered Amasa. The more plot there is in a sin, the worse it is. Joab contentedly sacrificed the interest both of the king and the kingdom to his personal revenge. But one would wonder with what face a murderer could pursue a traitor; and how, under such a load of guilt, he had courage to enter upon danger: his conscience was seared.