They brought him to Jerusalem (2Samuel 19)

The SAB marks 2Samuel chapter 19 as "boring", and yeah, it probably is; but what do you want, more mass killing and rape?

David is still mourning Absalom, and Joab goes to find him and says essentially that it's looking bad that he's mourning someone who wanted him and his family and friends dead, and if he wants to stay king, he needs to buck up and go talk with the people. So David goes and sits by the gate of the city, a traditional place for leaders to be, and the people notice and come to him. David sends word to the tribe of Judah (his own tribe) and asks why they haven't sent for him to come back, and tells Amasa that he will be the head of the army in Joab's place. They send for David, and he goes back to cross the Jordan.

A bunch of people show up at the crossing. Shimei shows up with a thousand Benjamiites and apologizes for the way he treated David on the way out. Mephibosheth shows up and says that he has been slandered by his servant. David is not in a mood for revenge at this moment, so he forgives them. An 80-year-old man named Barzillai, who helped David when he was in exile, shows up to see David back to Jerusalem, at least part of the way. David returns to Jerusalem, and there's a bit of an argument between the men of Judah and the men of the rest of Israel over who is more loyal, which apparently leads to problems in the next chapter.

Shimei the son of Gera, a Benjamite (2Samuel 16)

There's an interesting vignette at the beginning of 2Samuel 16 with Ziba, the servant of Mephibosheth. He shows up with a bunch of supplies for David, and David asks where Mephibosheth is. Ziba explains that apparently Mephibosheth is taking Absalom's insurrection as an opportunity to get political power (for who knows what reason), and David tells Ziba he can have all of Mephibosheth's property.

Then we see another interesting vignette with Shimei, some relative of Saul, who comes out to yell curses at David and throw rocks. Abishai asks to go over and kill Shimei, but David says to leave him alone, because maybe he deserves what Shimei is doing. This is interesting, because Saul was told to kill Agag, and failed to do so in a timely manner, and Haman, an Agagite, tried to kill the Jews in the book of Esther, but he was thwarted by Mordecai, a descendant of Shimei (see Esther 2:5). The SAB does point out that David asked Solomon to kill Shimei when he was on his deathbed, but perhaps by that time, he felt it was clear he had God's favor, and clearly Shimei was not doing the will of God, but just being an asshole.

So the chapter ends with Absalom arriving in Jerusalem, greeted by Hushai, David's spy. Hushai assures Absalom that he serves whoever the people choose as king. Ahithophel suggests to Absalom that he have sex with the concubines that David left behind, which, as I've pointed out before, was a common thing for new kings to do when they had conquered the former king. Indeed, as the SAB points out, this was foretold in chapter 12, and was said to be the consequences of what David did with Bathsheba. (See my interpretation of this "punishment" there.)

And his name was Mephibosheth (2Samuel 9)

2Samuel 9 is much easier than the last chapter. In fact, the SAB only really has one note, and it's absurdity, which I usually don't bother to address, since it's incredibly subjective.

David feels bad about the death of Saul and Jonathan, so he starts looking into whether Saul has any living descendants that he can show kindness to. He finds out Jonathan's son Mephibosheth is still alive, so he has him brought to him. When Mephibosheth arrives, he falls on his face, which is the "absurdity" the SAB notes. This is just Mephibosheth showing reverence to the king, not just because he's the king, but because he may be afraid of what David may do to him. David tells him not to be afraid, and informs him that he is going to see to it that he will give him everything that belonged to Saul, and furthermore, Mephibosheth is going to be a dinner guest of David forever.

See, David has a good side! (So much better than last chapter...)