These shall ye eat of all that are in the waters: whatsoever hath fins and scales in the waters, in the seas, and in the rivers, them shall ye eat.
These shall ye eat ... whatsoever hath fins and scales. 'The fins and scales are the means by which the excrescences of fish are carried off, the same as in animals by perspiration. I have never known an instance of disease produced by eating such fish; but those that have no fins and scales cause, in hot climates, the most malignant disorders when eaten: in many cases they prove a mortal poison' (Whitelaw).