Charles Ellicott Commentary Leviticus 11:47

"to make a distinction between the unclean and the clean, and between the living thing that may be eaten and the living thing that may not be eaten." — Leviticus 11:47 (ASV)

To make a difference. —Better, that you may put difference, as the Authorised Version renders the same word in Leviticus 10:10. That is, the design of the dietary law is to enable both the administrators of the law and the people to distinguish, by the characteristics and criteria specified above, between what is clean and unclean.

And between the beast that may be eaten. —From the fact that the same word, “beast,” is used in both clauses with regard to the animal which may be eaten and the one which may not be eaten without the qualifying adjunct “clean” and “unclean,” the administrators of the law during the second Temple concluded that the same clean animal is meant in both instances, under different conditions. The clean animal may be eaten when it is in a healthy state, but the same animal may not be eaten when it has organic defects, or is diseased. Hence they enacted the following canon: an animal is perfectly sound when it is capable of conceiving and bringing forth young. This is the reason why the Septuagint renders the word beast here by viviparous.