Israelite Man Examines a Clean Fishby emmanuel_higgins

Deuteronomy 14:10

And whatsoever hath not fins and scales ye may not eat; it is unclean unto you.

The instruction belongs to directions given through Moses forbidding the eating of unclean things, including swine and certain other animals. The forbidding of fish without fins and scales as unclean was not an arbitrary exercise of authority but was given to preserve the life and health of the people, because such foods could pollute the blood and shorten life. To retain the faculties of mind and body the blood must be kept pure by simple, healthful food, so the animals specified were those least objectionable for food.

The leading Jews who delighted in teaching and administering the law distorted these restrictions and carried this prohibition with the other regulations of eating and drinking to unreasonable lengths, requiring the straining of all water lest even the smallest speck or unclean insect render it unclean. This made life a burden of ceremonies and restrictions, keeping the mind on a continual strain in discriminating between clean and unclean and following a multitude of priestly injunctions, and keeping people in constant fear of infringing customs and traditions taught as law. By this endless round of forms minds were fastened upon external service to the neglect of true religion apart from Christ, a focus on trivial rules while grave sins were overlooked, which Jesus condemned.