Carl Friedrich Keil and Franz Delitzsch Old Testament Commentary

Lev 11:46, Lev 11:47 contain the concluding formula to the whole of this law. If we take a survey, in closing, of the animals that are enumerated as unclean and not suitable for food, we shall find that among the larger land animals they were chiefly beasts of prey, that seize upon other living creatures and devour them in their blood; among the water animals, all snake-like fishes and slimy shell-fish; among birds, the birds of prey, which watch for the life of other animals and kill them, the marsh-birds, which live on worms, carrion, and all kinds of impurities, and such mongrel creatures as the ostrich, which lives in the desert, and the bat, which flies about in the dark; and lastly, all the smaller animals, with the exception of a few graminivorous locusts, but more especially the snake-like lizards, - partly because they called to mind the old serpent, partly because they crawled in the dust, seeking their food in mire and filth, and suggested the thought of corruption by the slimy nature of their bodies. They comprised, in fact, all such animals as exhibited more or less the darker type of sin, death, and corruption; and it was on this ethical ground alone, and not for all kinds of sanitary reasons, or even from political motives, that the nation of Israel, which was called to sanctification, was forbidden to eat them. It is true there are several animals mentioned as unclean, e.g., the ass, the camel, and others, in which we can no longer recognise this type. But we must bear in mind, that the distinction between clean animals and unclean goes back to the very earliest times (Gen 7:2-3), and that in relation to the large land animals, as well as to the fishes, the Mosaic law followed the marks laid down by tradition, which took its rise in the primeval age, whose childlike mind, acute perception, and deep intuitive insight into nature generally, discerned more truly and essentially the real nature of the animal creation than we shall ever be able to do, with thoughts and perceptions disturbed as ours are by the influences of unnatural and ungodly culture. (Note: "In its direct and deep insight into the entire nexus of the physical, psychical, and spiritual world, into the secret correspondences of the cosmos and nomos, this sense for nature anticipated discoveries which we shall never make with our ways of thinking, but which a purified humanity, when looking back from the new earth, will fully understand, and will no longer only 'see through a glass darkly.'" - Leyrer, Herzog's Cycl.)