26 Now Joab fought against Rabbah of the Ammonites, and took the royal city. 27 Joab sent messengers to David, and said, "I have fought against Rabbah; moreover, I have taken the water city. 28 Now, then, gather the rest of the people together, and encamp against the city, and take it; or I myself will take the city, and it will be called by my name." 29 So David gathered all the people together and went to Rabbah, and fought against it and took it. 30 He took the crown of Milcom from his head; the weight of it was a talent of gold, and in it was a precious stone; and it was placed on David's head. He also brought forth the spoil of the city, a very great amount. 31 He brought out the people who were in it, and set them to work with saws and iron picks and iron axes, or sent them to the brickworks. Thus he did to all the cities of the Ammonites. Then David and all the people returned to Jerusalem.
Matthew Henry's Commentary on 2 Samuel 12:26-31
Commentary on 2 Samuel 12:26-31
(Read 2 Samuel 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.