Job 41:30

“Sharp stones [are] under him, etc.] And yet give him no pain nor uneasiness; he spreadeth sharp pointed things upon the mire; and makes his bed of them and lies upon them; as sharp stones, as before, shells of fishes, broken pieces of darts, arrows, and javelins thrown at him, which fall around him: this does not so well agree with the crocodile, the skin of whose belly is soft and thin; wherefore dolphins plunge under it and cut it with a thorn, as Pliny f1567 relates, or with spiny fins f1568; but with the whale, which lies among hard rocks and sharp stones, and large cutting pieces of ice, as in the northern seas.”

“stones--rather, "potsherds," that is, the sharp and pointed scales on the belly, like broken pieces of pottery. sharp-pointed things--rather, "a threshing instrument," but not on the fruits of the earth, but "on the mire"; irony. When he lies on the mire, he leaves the marks of his scales so imprinted on it, that one might fancy a threshing instrument with its sharp teeth had been drawn over it (Isa 28:27).”

“Sharp stones are under him - Margin, as in Hebrew, “pieces of pot sherd.” The Hebrew word (חדוד chaddûd), means “sharp, pointed”; and the phrase used here means “the sharp points of a potsherd,” or broken pieces of earthenware. The reference is, undoubtedly, to the scales of the animal, which were rough and pointed, like the broken pieces of earthenware. This description would not agree with the whale, and indeed will accord with no other animal so well as with the crocodile. The meaning is, that the under parts of his body, with which he rests upon the mire, are made up of sharp, pointed things, like broken pottery. He spreadeth sharp pointed things upon the mire - That is, when he rests…”

“Stones - His skin is so impenetrable, that the sharpest stones or shells are as easy unto him as the mire. Job 41:31”

“Sharp stones: Heb. Sharp pieces of potsherd he: So hard and impenetrable are his scales, that splinters of flint are the same to him as the softest reeds. Job 41:31”

“30 His under parts are the sharpest shards, He spreadeth a threshing sledge upon the mire. 31 He maketh the deep foam like a caldron, He maketh the sea like a pot of ointment. 32 He lighteth up the path behind him, One taketh the water-flood for hoary hair. 33 Upon earth there is not his equal, That is created without fear. 34 He looketh upon everything high, He is the king over every proud beast. Under it, or, תּחתּיו taken like תּחת, Job 41:11, as a virtual subject (vid., Job 28:5): its under parts are the most pointed or sharpest shards, i.e., it is furnished with exceedingly pointed scales. חדּוּד is the intensive form of חד (Arab. hadı̂d, sharpened = iron, p. 542, note), as חלּוּק, Sa1…”