(41-16) His heart is as firm as a stone; yea, firm as the nether millstone.
King James Version (KJV) - Job 41:24 >His heart is as firm as a stone; yea, as hard as a piece of the nether [millstone].
Berean Study Bible (BSB) - Job 41:24 >His chest is as hard as a rock, as hard as a lower millstone!