Here is a passage in the King James Version of 2 Samuel that rather arrests one's attention.
And David gathered all the people together, and went to Rabbah, and fought against it, and took it. . . . And he brought forth the spoil of the city in great abundance. 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 brick-kiln: and thus did he unto all the cities of the children of Ammon. So David and all the people returned unto Jerusalem (2 Sam. 12:29-31, KJV).
This certainly makes it sound as if King David practiced the most barbaric tortures on the civilians of an already-conquered city -- one thinks of Genghis Khan executing prisoners by pouring molten silver into their ears, or King Manasseh having Isaiah stuffed into a hollow tree and cut to pieces with a saw -- and there is not the slightest indication in the text that this was sinful or that the Lord disapproved.
Here's the Douay-Rheims version of the pertinent part of v. 31.
And bringing forth the people thereof he sawed them, and drove over them chariots armed with iron: and divided them with knives, and made them pass through brickkilns.
And here's the Wycliffe version.
And he led forth the people thereof, and sawed them, and did about them iron instruments of torment, and parted them with knives, and led them over by the likeness of tilestones.
However, most modern translations render the passage very differently. Here's the now-ubiquitous New International Version. (A footnote warns, "The meaning of the Hebrew for this clause is uncertain.")
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.
Recent translations almost universally follow this interpretation -- that the people were enslaved rather than tortured and killed. The New American Standard Bible followed the KJV as recently as its 1995 revision, but the 2020 revision follows the NIV.
Does this change represent some advance in the understanding of the Hebrew text, or simply a desire to put a more palatable interpretation on a shocking passage? My default assumption would be the latter, since recent decades have been rather more notable for their sensitivity and willingness to bowdlerize than for their sound linguistic scholarship.
I know basically no Hebrew, but based on an interlinear translation with grammatical notes, I think a literal reading is "and put them in a saw and in iron 'cuts' [also 'things cut' or 'cutting instruments'] and in iron axes and made them pass through in a brick-mold."
In defense of the enslavement reading, I note that Exodus 1:14 uses the same preposition-prefix ("in") to describe the kind of work the Hebrew slaves did in Egypt: "they made their lives bitter with hard bondage, in mortar, and in brick, and in all manner of service in the field."
In defense of the torture/murder reading, the various Old Testament references to idolators making their children "pass through the fire" to Molech -- pretty clearly a reference to human sacrifice or a ritual simulation thereof, not child labor -- use the same Hebrew verb for "pass through" as 2 Sam. 12:31. It's difficult to think what this verb could mean in the enslavement reading, even considering that it can also mean "pass over" -- maybe passing over the Jordan from Ammon to Jerusalem? Did David set some of the captives to labor with saws and axes in Ammon or elsewhere in Transjordan (perhaps because there was timber there?) and bring others back to Jerusalem to make bricks?
There's also the parallel passage in 1 Chronicles 20:3 to consider, but it is less helpful than it might be in resolving the question. The KJV reads, "And he brought out the people that were in it, and cut them with saws, and with harrows of iron, and with axes." (There are no brick-kilns in this version.) The verb cut seems to clear things up, but in fact it is a hapax legomenon, occurring nowhere else in the Bible, and the translation "cut" is just a guess. Strong's says it means "saw, cut," but also says it is identical to the word for "have power, reign" -- saying that the original sense of the latter was "vanquish," which is connected to sawing "through the idea of reducing to pieces." To me, though, the connection between reigning and forcing people to work is even clearer, so the ambiguity remains. English Bibles always translate it in keeping with their translation of 2 Sam. 12:31.
So, no final answer. I lean toward the KJV interpretation but have little confidence in that judgment.
What brought this passage to mind was 1 Kings 11:33.
Because that they [Solomon and his people] have forsaken me, and have worshipped Ashtoreth the goddess of the Zidonians, Chemosh the god of the Moabites, and Milcom the god of the children of Ammon, and have not walked in my ways, to do that which is right in mine eyes, and to keep my statutes and my judgments, as did David his father.
And I thought, Is this saying that worshiping pagan gods is worse than torturing people with saws and axes and burning them in a brik-kiln? Or just worse than enslaving them?