12 But Amasa lay in his blood in the middle of the road, and Joab's man saw that everyone was stopping to stare at him. So he pulled him off the road into a field and threw a cloak over him.

Matthew Henry's Commentary on 2 Samuel 20:12

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.