We have here an account of the conquest of Rabbah, and other cities of the Ammonites. Though this comes in here after the birth of David's child, yet it is most probable that it was effected a good while before, and soon after the death of Uriah, perhaps during the days of Bath-sheba's mourning for him. Observe, 1. That God was very gracious in giving David this great success against his enemies, notwithstanding the sin he had been guilty of just at that time when he was engaged in this war, and the wicked use he had made of the sword of the children of Ammon in the murder of Uriah. Justly might he have made that sword, thenceforward, a plague to David and his kingdom; yet he breaks it, and makes David's sword victorious, even before he repents, that this goodness of God might lead him to repentance. Good reason had David to own that God dealt not with him according to his sins, Psa 103:10. 2. That Joab acted very honestly and honourably; for when he had taken the city of waters, the royal city, where the palace was, and from which the rest of the city was supplied with water (and therefore, upon the cutting off of that, would be obliged speedily to surrender), he sent to David to come in person to complete this great action, that he might have the praise of it, Sa2 12:26-28. Herein he showed himself a faithful servant, that sought his master's honour, and his own only in subordination to his, and left an example to the servants of the Lord Jesus, in every thing they do, to consult his honour. Not unto us, but to thy name, give glory. 3. That David was both too haughty and too severe upon this occasion, and neither so humble nor so tender as he should have been. (1.) He seems to have been too fond of the crown of the king of Ammon, Sa2 12:30. Because it was of extraordinary value, by reason of the precious stones with which it was set, David would have it set upon his head, though it would have been better to have cast it at God's feet, and at this time to have put his own mouth in the dust, under guilt. The heart that is truly humbled for sin is dead to worldly glory and looks upon it with a holy contempt. (2.) He seems to have been too harsh with his prisoners of war, Sa2 12:31. Taking the city by storm, after it had obstinately held out against a long and expensive siege, if he had put all whom he found in arms to the sword in the heat of battle, it would have been severe enough; but to kill them afterwards in cold blood, and by cruel tortures, with saws and harrows, tearing them to pieces, did not become him who, when he entered upon the government, promised to sing of mercy as well as judgment, Psa 101:1. Had he made examples of those only who had abused his ambassadors, or advised or assisted in it, that being a violation of the law of nations, it might have been looked upon as a piece of necessary justice for terror to other nations; but to be thus severe with all the cities of the children of Ammon (that is, the garrisons or soldiers of the cities) was extremely rigorous, and a sign that David's heart was not yet made soft by repentance, else the bowels of his compassion would not have been thus shut up - a sign that he had not yet found mercy, else he would have been more ready to show mercy.

And have taken the city of waters - The city where the tank or reservoir was that supplied the city and suburbs with water. Some think that the original, לכדתי את עיר המים lachadti eth ir hammayim, should be translated I have intercepted, or cut off, the waters of the city: and Houbigant translates the place, et aquas ab urbe jam derivavi; "And I have already drawn off the waters from the city." This perfectly agrees with the account in Josephus, who says των τε ὑδατων αυτους αποτεμνομενος, having cut off their waters, Antiq., lib. vii., cap. 7. This was the reason why David should come speedily, as the citadel, deprived of water, could not long hold out.

Now therefore gather the rest of the people together,.... The rest of the soldiers in the land of Israel, and come to Rabbah:

and encamp against the city; invest it in form:

and take it; upon a surrender or by storm; for it could not hold out long:

lest I take the city, and it be called after my name; so great a regard had Joab, though an ambitious man, to the fame and credit of David his king: so Craterus (a) at the siege of Artacacna, being prepared to take it, waited the coming of Alexander, that he might have the honour of it.

(a) Curt. Hist. l. 6. c. 6.

the city of waters--Rabbah, like Aroer, was divided into two parts--one the lower town, insulated by the winding course of the Jabbok, which flowed almost round it, and the upper and stronger town, called the royal city. "The first was taken by Joab, but the honor of capturing so strongly a fortified place as the other was an honor reserved for the king himself."