(6) And David said to Abishai, Now shall Sheba the son of Bichri do us more harm than did Absalom: take thou thy lord's servants, and pursue after him, lest he get him fenced cities, and escape us. (7) 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.
It is somewhat extraordinary, that as Joab was degraded from being Captain of the host, he should still be in the army; yet so it was.