(26) Took the royal city.--The parallel narrative is resumed at this point in 1Chronicles 20:2. Rabbah was situated in the narrow valley of the upper Jabbok, on both sides of the stream, but with its citadel on the cliff on the northern side. The "royal city" of this verse, and "the city of waters" of the next, refer probably to the city proper, while the "city" of 2Samuel 12:28-29 is no doubt the citadel, which was more strongly fortified.

Verse 26. - Joab... took the royal city. As the siege of Rabbah would be conducted by the slow process of blockade, it might easily be prolonged into the second year, and so give ample space for David's sin and its punishment by the death of the child. But more probably the narrator, having commenced the history of David's sin, completes the story before returning to his account of the war. Thus the capture of Rabbah would occupy some of the interval between David's adultery and Nathan's visit of rebuke, and would lessen the difficulty, which we cannot help feeling, of David remaining for nine or ten months with the guilt of adultery and murder resting upon him, and no open act of repentance. Some short time, then, after Uriah's death, Joab captured "the city of waters." This is not a poetical name for Rabbah, but means the "water city," that is, the town upon the Jabbok, whence the supply of water was obtained. The citadel, which occupied a high rock on the northwestern side, must, therefore, soon be starved into submission, and the whole of "the royal city," that is, of the metropolis of the Ammonites, be in Joab's power. He therefore urges David to come in person, both that the honour of the conquest may be his, and also because probably the blockading force had been reduced to as small a body of men as was safe, and the presence of a large army was necessary for completing the subjugation of the country, which would follow upon the capture of the capital.

12:26-31 To be thus severe in putting the children of Ammon to slavery was a sign that David's heart was not yet made soft by repentance, at the time when this took place. We shall be most compassionate, kind, and forgiving to others, when we most feel our need of the Lord's forgiving love, and taste the sweetness of it in our own souls.And Joab fought against Rabbah of the children of Ammon,.... Of his being sent against it, and of his besieging it, we read in 2 Samuel 11:1; but it can hardly be thought that he had been so long besieging it, as that David had two children by Bathsheba; but the account of the finishing of it is placed here, that the story concerning Bathsheba might lie together without any interruption:

and took the royal city; or that part of it in which the king's palace was, and which, as Abarbinel observes, was without the city, as the palaces of kings now usually are.