1 Chronicles 20:3

Harrows. Hebrew, "cut them with saws, and with harrows; (Haydock) or, rollers of iron, and with saws." But some other term was probably used, as we find saws before. (Calmet) --- Protestants have "axes." This exemplary punishment was in consequence of the violation of the law of nations. Abulensis pronounced it lawful. Tirinus accuses David of a grievous sin of cruelty; observing that he was at this time involved in the sin of adultery: and people easily fall from one abyss into another. Cruelty and lust often go together. Yet it seems best to suspend our judgment. (Haydock) --- David might only treat the most guilty in this manner. (Du Hamel)