Leviticus 11:10

And all that have not fins nor scales in the seas, and in the rivers ,.... Such as eels, lampreys, &c.;

of all that move in the waters, and of any living thing which is in the waters ; the former of these are interpreted by Aben Ezra and Ben Gersom of little fishes that have but a small body, and such as are created out of the waters; and the latter, of such as are produced of a male and female; or, as Maimonides F18 Hilchot Maacolot Asuret, l. 1. c. 2. sect. 12. explains it, the one signifies the lesser creatures, such as worms and horse leeches; the other greater ones, sea beasts, as sea dogs, &c.;

they shall be an abomination to you ; not only unclean, and so unfit to eat, but to be had in abhorrence and detestation, as being exceeding disagreeable and unwholesome; and, as a learned man observes F19 Scheuchzer. ut supra, (Physic. Sacr. vol. 2.) p. 287. , to these prohibited in general belong all those animals in lakes, rivers, or seas, which are of a slow motion, and which, because of the slow motion of their bodies, do not so well digest their food; and for that may be compared with four footed beasts that have but one belly, and so unwholesome as they.