7 And there went out after him Joab's men and the Cherethites and the Pelethites, and all the mighty men. They went out from Jerusalem to pursue Sheba the son of Bichri.

Matthew Henry's Commentary on 2 Samuel 20:7

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.