Leviticus 11:21

Yet these may ye eat of every flying creeping thing that goeth upon all four, which have legs above their feet, to leap withal upon the earth; Yet these may ye eat ... that goeth upon all four. The locusts, like all insects, have six feet; but the sacred historian notices the different direction of the two anterior from the four posterior legs of insects; for, as he speaks of them as going upon four legs, it is evident that he considered the two anterior as arms (Kirby and Spence, 'Introduction to Entomology,' 1:, p. 24). He also shows an acquaintance with the distinctions which separate the Gryllidoe into different genera. The locusts, which belong to the order Orthoptera, are subdivided into two large groups-the first, the cursoria, runners or creepers, were unclean, and of course interdicted food by the law; the second, the saltatoria, or leapers, which formed a large division, are herbivorous, and the principal genera of them are mentioned in this passage.

Legs above their feet, х kªraa`ayim (H3767)] - the tibiae, the part of the legs from the knee to the ankle; so called as being bent under in kneeling or lying down (Gesenius); applied to the feet of the locust, which are adapted for leaping or skipping. The singular expression in our version - "having legs above their feet" - means, that the tibiae were placed in such a manner above the tarsi as to fit the creatures for leaping.