David brought out the people who were there and put them to work with saws, iron picks, and axes, and he made them work at the brick kilns. He did the same to all the Ammonite cities. Then David and all his troops returned to Jerusalem.
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.
Commenting on 2 Samuel 12:26-31
he brought forth the people . . . and put them under saws, &c.--This excessive severity and employment of tortures, which the Hebrews on no other occasion are recorded to have practised, was an act of retributive justice on a people who were infamous for their cruelties (Sa1 11:2; Amo 1:13). Next: 2 Samuel Chapter 13
And he brought forth the people that [were] therein, and put [them] under saws, and under harrows of iron, and under axes of iron, and made them pass through the brickkiln: and thus did he unto all the cities of the children of Ammon. So David and all the people returned unto Jerusalem. (t) Signifying that as they were malicious enemies of God, so he put them to cruel death.