30. 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).
JFB.
Picture Study Bible