David now had another rebellion on his hands; it may not have been as large as the one with Absalom, but it was a threat that had to be crushed. David calls for his new commander, Amasa, to lead the forces to quell the rebellion. Keil & Delitzsch says this was the new general’s opportunity to have his first step fulfilled and receive the promise from David to be Israel’s new army general. However, it is likely the men of Israel did not hold any allegiance to him, and when Joab took matters into his own hand that might give reason why there was no outcry at the audacity of this murderous act (20:1-13). Now having taking control of the army, Joab seeks to remedy the king of any further threat to the nation. In short order the threat was eliminated.
Application: Joab may not have realized it at the time – ambition has a way of clouding one’s vision – but he had sown the seed for his own destruction. David felt threatened by Joab, but had not the capability (he felt) to tend to him properly. It was to Solomon that he gave his final words pertaining to him. The Scripture says that we can be sure our sin will find us out (Numbers 32:23). It matters not how much time as elapsed, how much good we have done to put the past behind us, or how we have manipulated situations to bury the deed (or deeds) of the past. In time, the seed we had sown will sprout. Is there anything in your past you have not addressed with the Lord? Do it now. The seed may bloom, but if the Lord is one your side the seed that will surely blossom will die.