31 and brought out the people who were there, consigning them to labor with saws and with iron picks and axes, and he made them work at brickmaking.[1] David did this to all the Ammonite towns. Then he and his entire army 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.