The questions return to the subject of capturing Leviathan. New English Bible places this verse after 40.24.

Can you fill his skin with harpoons translates the Hebrew literally and is ambiguous. Fill his skin means “pierce his skin with many harpoons.” Harpoons in this line and fishing spears in the next line occur only here in the Old Testament. The word for harpoons is connected with a word for “thorn” used in Numbers 33.55. It is not certain just how this instrument was made, but from its association with “thorn” it was probably a barbed spear, and the fishing spears must have been very similar, and also thrown by hand. One of these, or even both, may have been attached by a rope to a boat or held in the hand to prevent the weapon from being taken away by the wounded animal. The point of the question is that no amount of spearing the hide or the head of Leviathan would injure or kill it. Harpoons and fishing spears may have to be translated by a single term in some languages, or through the use of a descriptive phrase such as “spears used for killing fish.”

Quoted with permission from Reyburn, Wiliam. A Handbook on Job. (UBS Helps for Translators). New York: UBS, 1992. For this and other handbooks for translators see here .