Matthew Poole and continuators on Job 41:7

7. Canst thou fill his skin with barbed Irons, or his head with fish-spears ?

This may be understood, either 1. of the Whale. And whereas it is objected, that the Whales at this day are taken in this manner, and therefore this cannot be understood of them, it may be replied, both that this art and way of taking Whales is a late invention, and was not known in Iob's time, and that he doth not speak of the absolute impossibility, but of the great difficulty of taking them. Or 2. of the Crocodile, whose skin is so hard that an Iron or Spear will not pierce it, as we shall see hereafter.