Leviticus 7:25

25. Of the beast, of which men offer This is evidently an interdict of the fat of the entire class of sacrificial animals, and not of the particular victims. Fat promotes cutaneous diseases. The prohibition of this article of diet also raised up a barrier between the Israelites and the idolatrous nations by restraining the former from partaking of the festive banquets of the latter. Michaelis suggests that the prohibition of fat was for the purpose of promoting the culture of the olive, and Knobel maintains that it was because the mouth of man is unclean. A better reason is, because it would be an infringement of Jehovah’s rights to eat as common food that which he had sanctified unto himself.