(21) Of every flying creeping thing.--Rather, of all winged creeping things. Having laid down the general rule that those creatures which creep along upon their feet in the manner of quadrupeds, and which have also wings, must not be eaten, the Lawgiver now mentions those which form an exception.

Which have legs above their feet.--Better, which have knees above their hinder legs, that is, those which have the third or hindmost pair of legs much longer and stronger than ordinary insects. Those insects, therefore, in whose hindermost legs the second joint is much larger and stronger, whereby they are enabled to leap or raise themselves up with great force and leap a great distance upon the earth, are excepted. These are the locusts. The canonical law which obtained during the second Temple defines more minutely the characteristics of clean locusts. A clean locust we are told has (1) four front feet, (2) four wings, (3) two springing feet, and (4) the wings so long and broad that they cover the greater portion of the back body of the insect. If it possesses these four characteristics it is clean, whether it is with a tail or without it, and whether it has an oblong or round head.

11:1-47 What animals were clean and unclean. - These laws seem to have been intended, 1. As a test of the people's obedience, as Adam was forbidden to eat of the tree of knowledge; and to teach them self-denial, and the government of their appetites. 2. To keep the Israelites distinct from other nations. Many also of these forbidden animals were objects of superstition and idolatry to the heathen. 3. The people were taught to make distinctions between the holy and unholy in their companions and intimate connexions. 4. The law forbad, not only the eating of the unclean beasts, but the touching of them. Those who would be kept from any sin, must be careful to avoid all temptations to it, or coming near it. The exceptions are very minute, and all were designed to call forth constant care and exactness in their obedience; and to teach us to obey. Whilst we enjoy our Christian liberty, and are free from such burdensome observances, we must be careful not to abuse our liberty. For the Lord hath redeemed and called his people, that they may be holy, even as he is holy. We must come out, and be separate from the world; we must leave the company of the ungodly, and all needless connexions with those who are dead in sin; we must be zealous of good works devoted followers of God, and companions of his people.
]Yet these may ye eat,.... Which are after described and named:

of every flying creeping thing that goeth upon all four; even though it is a creeping thing that flies and goes upon four feet, provided they be such:

which have legs above their feet, to leap withal upon the earth; there is a double reading of this clause; the textual reading is, "which have not legs", and is followed by several interpreters and translators; and the marginal reading, which we follow, is, "which have legs"; and both are to be regarded as true, and written by Moses, as Ainsworth observes; for locusts are born without legs, and yet creep low, as Pliny asserts (z), and they have them afterwards; and it is a canon of the Jews, that what have not legs or wings now, or have not wings to cover the greatest part of them, but shall have after a time when grown up, these are as free (to eat) now, as when grown up (a). Dr. Shaw thinks (b) the words may bear this construction, "which have knees upon" or "above their hinder legs, to leap withal upon the earth"; and applying this to the locust afterwards, and only instanced in, he observes, that this has the two hindermost of its legs and feet much stronger, larger, and longer than any of the foremost. In them the knee, or the articulation of the leg and thigh, is distinguished by a remarkable bending or curvature, whereby it is able, whenever prepared, to jump, to spring, or raise itself up with great force and activity. And these Aristotle (c) calls the leaping parts; and though he attributes to the locust six feet, as does also Pliny (d), yet he takes the two leaping parts into the account; whereas Moses distinguishes those two from the four feet; and so Austin (e) observes, that Moses does not reckon among the feet the two hinder thighs with which locusts leap, which he calls clean, and thereby distinguishes them from such unclean flying creatures which do not leap with their thighs, such as beetles; and so the Jewish writers always describe a clean locust as having four feet, and two legs, thighs, or knees. Maimonides (f) gives three signs of them, which are these, whatsoever has four feet and four wings, which cover the greatest part of its body in length, and the greatest part of the compass of it, and has two thighs or knees to leap with, they are of the clean kind; and although its head is long, and it hath a tail, if its name is "chagob" (a locust) it is clean.

(z) Nat. Hist. l. 11. c. 29. (a) Maimon. ib. c. 1. sect. 23. (b) Travels, p. 420. (c) De Part. Animal. l. 4. c. 6. (d) Nat. Hist. l. 11. c. 48. (e) Retract. l. 2. c. 15. (f) Maacolot Asurot, c. 1. sect. 22.