Bible Notes Online - 2-Samuel 20 - ESV
Commentary

v1-2: In the midst of the argument between Judah and Israel, Sheba arose, to turn Israel against David. This was another Benjamite, like Saul and Shimei, who attacked David. The people were blown about by another influential man. We are called to remain loyal to our King.

v3: This verse belongs at the end of ch 19, but David had not even reached Jerusalem by the time Sheba rose up against him. The ten concubines were those who had been mistreated by Absalom (16.21-22).

v4-5: David had appointed Amasa as the commander of his army, in place of Joab, see 19.13. Amasa's delay put David in difficulty, and opened the door for Joab to kill Amasa.

v6-7: David asked Abishai to lead his army to pursue Sheba. They had to capture Sheba quickly, or he would escape, and gather strength again.

v8-10: Joab took the opportunity to kill Amasa, as he had Abner.

v11-13: An indication of Joab's popularity, and power over the people; the cry of Joab's soldier inferred that support for David meant support for Joab.

v14-17: Joab pursued Sheba to Abel Beth Maacah, or just Abel. Sheba had gathered a small army together, even though only Judah had sided with David.

Absalom and Sheba may both be said to be opportunists, but Absalom had given time to gathering support, whereas Sheba seems to have acted on impulse, and failed to gather sufficient real support.

v18-22: At Abel disputes were settled, or the answer was given. Here Sheba's rebellion was subdued and ended. Further, the King's position was made more secure.

Joab did not realise the irony of his own words, "Far be it from me to swallow up or destroy!" He frequently destroyed others.

v23-26: Joab had taken back his role as commander of David's army. He was successful, but clearly unspiritual.

After the rebellions under Absalom and Sheba were ended, David's reign ended more peacefully. Even so, the prophecy of Nathan (12.10) had been fulfilled.