John Calvin Commentary Leviticus 11:9

"These may ye eat of all that are in the waters: whatsoever hath fins and scales in the waters, in the seas, and in the rivers, that may ye eat." — Leviticus 11:9 (ASV)

These shall you eat of all that are in the waters. Here, also, some who know little of religion plausibly contend that God is acting as a physician, distinguishing wholesome from unwholesome food. But although their opinion is sufficiently refuted by physicians themselves, yet, even if I were to grant what they claim, they reason poorly.

For God's purpose was different from providing for the people’s health. Because He was dealing with an unsophisticated people, He chose common signs, by which, being instructed, they might gradually ascend to higher things.

It would be useless to follow the allegories Isychius has invented,⁴⁴ and I would willingly consign these trivialities to oblivion, except that many have such an inclination towards subtleties that sensible views would hardly satisfy them until the foolishness of these allegories has been exposed. I will say nothing of the scales and fins.

If, at first glance, anyone approves of his claim that the fishes' names are omitted because the Church does not seek a name on earth, and that fish signify the Church, they should consider several points. Is it consistent for the Church to exist only in the water? Furthermore, should the birds, which are nearer to heaven, be excluded from this honor? Thirdly, should the clean animals be rejected, as if they did not belong to the Church? And lastly, should those who by their contagion pollute the Church be counted among the elect, whose names are written in heaven? For certainly, many fish are unclean.

Those who will not accept these clear reasons, I will let them wander in their labyrinth.

This simple view—that the fish are not named because most of them were unknown to the Jews, whose land did not produce many river fish since it hardly had any river besides the Jordan, while sea fish only visited the neighboring shores—will satisfy the moderate and teachable.

⁴⁴ “Hesychius, observing that no proper names are given here or elsewhere in Scripture, as I have said, to fishes, interprets it of the Gentiles gathered into the Church, whose names she does not desire to be written on earth, but in another generation, and in heaven; that these are born again in the waters of baptism; that they have of baptism; that they have fins, in the meditation of the law, which corresponds with the sublime and heavenly life; and in the meditation of the law, which corresponds with the sublime and heavenly life; and scales, which may be easily removed, as also they may easily lay aside their ignorance, even as which may be easily removed, as also they may easily lay aside their ignorance, even as scales are said to have fallen from the eyes of Paul when he was converted. He declares that the adulterer, the covetous man, the drunkard, and the calumniator, have not are said to have fallen from the eyes of Paul when he was converted. He declares that the adulterer, the covetous man, the drunkard, and the calumniator, have not fins, since their life is sordid and unclean; and says that the worshipper of idols cannot be counted among those who have , since their life is sordid and unclean; and says that the worshipper of idols cannot be counted among those who have scales, since he seems to be possessed of a hard and since he seems to be possessed of a hard and shellfish-like, and incurable ignorance of divine thingsand incurable ignorance of divine things.” —— Lorinus, in loco.