(24) His heart--i.e., his nature, his disposition. This seems to be the meaning, rather than the physical organ of life.

Verse 24. - His heart is firm as a stone. Some regard this as intended physically, and note that the great saurians, with their cold and sluggish circulation, have hearts which are comparatively torpid, not contracting or expanding readily. Others take the "stony heart" to mean a fierce and obstinate disposition. In either case, the description will well suit the crocodile. Yea, as hard as a piece of the nether millstone. A repetition and slight exaggeration of the preceding idea.

41:1-34 Concerning Leviathan. - The description of the Leviathan, is yet further to convince Job of his own weakness, and of God's almighty power. Whether this Leviathan be a whale or a crocodile, is disputed. The Lord, having showed Job how unable he was to deal with the Leviathan, sets forth his own power in that mighty creature. If such language describes the terrible force of Leviathan, what words can express the power of God's wrath? Under a humbling sense of our own vileness, let us revere the Divine Majesty; take and fill our allotted place, cease from our own wisdom, and give all glory to our gracious God and Saviour. Remembering from whom every good gift cometh, and for what end it was given, let us walk humbly with the Lord.His heart is as firm as a stone; yea, as hard as a piece of the nether millstone. Which must be understood not of the substance but of the qualities of it, being bold, courageous, undaunted, and unmerciful; which is true both of the whale and crocodile, and particularly of the crocodile: Aelianus (z) relates of one sort of them that they are unmerciful, though elsewhere (a), he represents them as fearful.

(z) De Animal. l. 12. c. 41. (a) Ibid. l. 10. c. 24.