31 He brought forth the people who were therein, and put them under saws, and under iron picks, and under axes of iron, and made them pass through the brick kiln: and he did so to all the cities of the children of Ammon. David and all the people returned to Jerusalem.
Matthew Henry's Commentary on 2 Samuel 12:31
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.