2 Samuel 12:31 - Wesley's Explanatory Notes

The people — The words are indefinite, and therefore not necessarily to be understood of all the people; but of the men of war, and especially of those who had been the chief actors of that villainous action against David's ambassadors, and of the dreadful war ensuing upon it; for which, they deserved severe punishments. Altho' indeed there seems to have been too much rigour used; especially, because these deaths were inflicted not only upon those counsellors, who were the only authors of that vile usage of the ambassadors; but upon some number of the people. And therefore it is probable, David exercised this cruelty whilst his heart was hardened, and impenitent; and when he was bereaved of that good spirit of God, which would have taught him more mercy. Saws — He sawed them to death of which punishment, we have examples both in scripture, and in other authors. Brick — kiln — Or, made them to pass through the furnace of Malchen: that is, of Moloch; punishing them with their own sin, and with the same kind of punishment which they had inflicted upon their own children.