He brought out the people who were in it, and put them under saws, under iron picks, 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. Then David and all the people returned to Jerusalem.
2 Samuel 12:29 David gathered all the people together, and went to Rabbah, and fought against it, and took it.
2 Samuel 12:30 He took the crown of their king from off his head; and its weight was a talent of gold, and in it were precious stones; and it was set on David’s head. He brought a great quantity of plunder out of the city.
2 Samuel 12:31 He brought out the people who were in it, and put them under saws, under iron picks, 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. Then David and all the people returned to Jerusalem.
The verse centers on "brought", "people", "under", "saws", "iron", and "picks". It is saying that the verse draws attention to "brought" and "people", so its meaning should be read from those terms before moving to application.
The prior verse says "He took the crown of their king...", giving immediate footing for "brought" and "people". In 2 Samuel context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "brought" and "people" with trust shaped by these words, not by a vague optimism outside the passage.