Was Joab removed from his office after assassinating Abner?

Question

2 Samuel 2 has Joab as the commander of David's army during David's 7-year reign at Hebron.

1 Chronicles 11 is about the conquest of the city of Jerusalem, at the beginning of the United Kingdom of Israel, years after the incidents in 2 Samuel 2 and 3. Verses 4-6 read:

⁴ David and all the Israelites marched to Jerusalem (that is, Jebus). ⁵ The Jebusites who lived there said to David, “You will not get in here.” Nevertheless, David captured the fortress of Zion—which is the City of David. ⁶ David had said, “Whoever leads the attack on the Jebusites will become commander in chief.” Joab son of Zeruiah went up first, and so he received the command."

Why was David looking for a commander-in-chief if he already had Joab filling that position for years?

Answer 1

Whether Joab was commander-in-chief or one of several commanders of David's army at the time, the answer to the OP headline question is "no," Joab was not dismissed from his office when he killed Abner. The OP's secondary question - Why was David looking for a commander-in-chief if he already had Joab filling that position for years? - is a little trickier. The most likely explanation is that after Joab's treacherous murder of Abner, his reputation among the other captains suffered. David used the attack on Jerusalem to remove any objections to Joab's leadership.

David's reticence to punish Joab is considered a very serious problem by commentators such as John Schultz, who says:

Joab’s murder of Abner was premeditated and David ought to have ordered Joab’s execution. The fact that he did not act according to the Word of God at this time bound him to Joab for the rest of his life. David must have thought that he would lose his whole army if Joab were removed. But Joab’s murder of Abner could have cost David all the tribes of Israel with the exception of Judah.

Some commentators (e.g. The Interpreters Bible 1-vol. Commentary) have even seen the episode as possibly pre-planned by David and Joab to allow David to be free from guilt in Abner's death since Joab could claim a blood-debt from Abner (2 Sam:2:23). In this scenario, David's public display of grief for Abner would be designed to assuage the feelings of the northern tribes, among whom Abner was well respected. The death of Abner left any question of a resurgent military threat from the House of Saul moot. Together with the victory at Jerusalem it would not be long until David united all 12 tribes under his leadership, with Joab as his strong right arm.

Whatever the reason and whatever office Joab held at the time, David did not dismiss Joab from his position for the crime. David gave Joab an opportunity to prove his worthiness as "commander-in-chief" through his successful attack on Jerusalem. Joab would prove to be both an important asset to David and a thorn in his side throughout his life.

Answer 2

Joab was never appointed to an office before his formal appointment following the capture of Jerusalem. before that time, various people were the defacto leaders of the army.

• Before David became king of Judah (as recorded in 2 Sam 2) he had been a local war-lord with a group of 600 loyal followers. 1 Sam 23:13, 27:2, 30:9, etc.
• At the time of David's anointing as king of Judah in 2 Sam 2, three people were leading the informal "army" of Israel which was merely an extension of his 600 loyal followers. According to 2 Sam 2:18 these were the three sons of David's older sister, Zeruiah, viz, Joab, Abishai and Asahel. Of these Joab was the most senior and the strongest.
• Asahel died in the battle of Gibeon (2 Sam 2:22-24).
• Even toward the end of David's life, Abishai was still one of the leading generals of Israel's army (along with Ittai) as recorded in 2 Sam 18:5.

On two occasions, David appointed others as head of the army, and but Joab murdered both of them to again became leader of the army:

• Abner was appointed and soon murdered by Joab, 2 Sam 3
• Amasa was appointed over the army after the sedition of Absolom (2 Sam 19:13) but was subsequently murdered by Joab (2 Sam 20:8-13)

It was this kind of brutal self-assertiveness that caused David to exclaim,

"these sons of Zeruiah are too strong for me" 2 Sam 3:39

The first record we have of Joab's formal appointment as chief general of the Israelite army is in 2 Sam 8:16 which followed Joab's successful assault and capture of Jerusalem.

Answer 3

One posssible answer is to be aware that there were different levels of leadership.

For example, 2 Samuel ch9 vv16-18 distinguishes between Joab as leader of the army and Benaiah son of Jehoiada as leader of the Cherethites and Pelethites (I assume this is the same role as "over David's bodyguard" in 2 Samuel ch23 v23). I would take "the army" in that description as a reference to the "host" of the people at large, called out for emergencies, while Benaiah commanded the foreign-born mercenaries and Abishai commanded the "thirty" (2 Samuel ch23 v19), the hand-picked home-grown professionals.

But if David did not take the field in person, somebody else would have to take overall command of his military forces as a whole and lead them into battle. That was exactly what Joab was doing in 2 Samuel ch11. The Chronicles story could be telling us why David gave him that additional role.