His heart is as firm as a stone; Yea, firm as the nether millstone.

His heart is as strong as a stone, hard as the lower crushing-stone.

Η καρδια αυτου ειναι στερεα ως λιθος· σκληρα μαλιστα ως η κατω μυλοπετρα.

His heart is as firm as a stone; yea, as hard as a piece of the nether millstone.