The first time we read of clean and unclean animals is when Noah went into the ark: he was instructed to take seven pairs of each of the clean beasts and clean fowls and only two of the unclean; we have no instructions as to how Noah distinguished them, but it shows that in early days there was a distinction between the clean and unclean. Those called 'clean' were doubtless clean for sacrifice, and not for food, as nothing is said of man eating animal food till after the flood, and then "every moving thing" was given for food. When Noah came out of the ark he offered of every clean beast and every clean fowl for burnt offerings. Ge 7:2; 8:20.

With Israel it was different. What animals were to be offered are distinctly specified, and what animals might be eaten as clean and what might not be eaten as unclean are given in detail. Of beasts the clean were those that divided the hoof and chewed the cud: those that had only one of these distinguishing marks were unclean. Of the fishes those only were to be eaten which had fins and scales. Of the fowls a list is given of those that must not be eaten, and of the winged crawling things, that go on all fours, only those 'which have legs above their feet to leap with' might be eaten. The locust, the bald locust, the beetle, and the grasshopper, each after his kind, might be eaten (probably four species of locust); but all other flying, creeping, or swarming things, which have four feet were unclean. 'Every creeping thing that creepeth upon the earth' was unclean whatsoever goeth upon the belly, and whatsoever goeth upon all fours, or hath a multitude of feet, among all creeping things, was unclean. These directions are respecting what might or might not be eaten. Those that were not to be eaten were to be regarded as an abomination, and if the dead bodies of any such fell upon any vessel or garment it rendered it unclean, and any one who touched their carcass must wash his clothes and be unclean until the evening. Lev. 11; De 14:3-20. These animals in their habits and instincts were used of God to teach His people as to habits and ways of the flesh that were unclean in His sight.

We know from other scriptures that the animals described here as unclean are not really so, but good as creatures of God; yet they were by Israel to be regarded as unclean and an abomination. The unclean are mostly those that are flesh-eating.

The particulars given of the unclean have doubtless symbolical meanings. They are principally these:

1. Dividing the hoof and chewing the cud may point to a steady patient walk (as the camel or the ox), and the digesting or meditating upon what is received: cf. Ps 1:1-2; Pr 12:27.

2. Everything that creepeth upon the earth was unclean: the earth is under the curse because of sin, and there must be a moral rising above it.

3. The fish must have fins and scales: the fins enable a fish to rise in the water, to direct its course, and to avoid danger, and the scales are its protection. To escape the pollutions of the world a circumspect walk is needed and also having on the protection which God has provided.

It is clear from scripture that the prohibition of certain creatures as unclean affected Israel only, and the vision given to Peter manifests that this restriction is done away in Christ. It is plainly declared that "every creature of God is good, and nothing to be refused if it be received with thanksgiving; for it is sanctified by the word of God as in Ge 9:3 and prayer." 1Ti 4:4-5.