“Do not eat any of the hard fat (cheilev) in an ox, sheep, or goat.” (Lev. 7:23)
Some commentaries (Maimonides, Guide, III:48; Sefer HaChinuch, mitzvah 147) explain that the Torah prohibits eating these fats for health reasons. Yet, if this were true, why is only the cheilev of these three animals forbidden?
Curiously, we find that the mitzvah of kisuy ha-dam, covering the blood after slaughtering, only applies to non-domesticated animals and fowl. Why does the Torah not require kisuy ha-dam also for cattle, sheep, and goats? Why do these two mitzvot, both of which pertain to the preparation of kosher meat, apply to two mutually exclusive groups of animals?
If we analyze the degree of sensitivity one should have when taking the life of an animal for food, we should differentiate between two categories of animals. The first category consists of animals that we do not feed and raise. These are wild animals that are hunted and killed. All birds are included in this category, as they usually need to be trapped.1
We should feel embarrassment when we must stoop to such ignoble and cruel behavior. Therefore, when stalking and killing untamed animals and birds, the Torah commands us to cover the blood, a sign of our inner shame at this merciless act. “If any man... traps a wild animal or bird that may be eaten and sheds its blood, he must cover the blood with earth” (Lev. 17:13).
The second category of animals is comprised of domesticated beasts: cattle, sheep, and goats. We raise and feed them for their milk, wool, and labor. Not to kill these animals for food after they approach old age and are much less productive, requires a higher and more refined sense of ethical sensitivity. Regarding this category of animals, who become a burden to their owner in old age, the Torah does not require that their blood be covered after their slaughter. We need not feel the same extent of embarrassment as when taking the life of a wild animal.
Nonetheless, the Torah created for domesticated animals a special prohibition to remind us that we should only take their lives for our essential needs. This is the purpose of the prohibition of cheilev. We are permitted to slaughter these animals for their meat, to give us energy and strength, but they should not be killed for the sake of their fats. We should not kill them merely for the pleasure of eating their fatty meat, so pleasurable to the palate of the gastronome. The prohibition of cheilev emphasizes that we should only take their lives out of genuine necessity.
Why does the Torah not prohibit eating the fats of birds and wild animals? We should feel ashamed at this cruel act, regardless of whether our intent is for pure enjoyment or true need. If the Torah distinguished between their meat and their fats, this would only obscure the moral impact of covering their blood, a sign of our profound embarrassment over spilling the blood of a free animal, no matter what the circumstances.
(Gold from the Land of Israel. Adapted from Otzarot HaRe’iyah vol. II, p. 95)
1 Of course, this was more applicable in the days when chickens and other poultry were allowed to roam freely, not cooped up in small cages.