leviticus 3:4 And the two kidneys, and the fat that is on them, which is by the flanks, and the caul above the liver, with the kidneys, it shall he take away. - Free Bible Online

      4-11. the two kidneys . . . of the flock . . . the whole rump--There is, in Eastern countries, a species of sheep the tails of which are not less than four feet and a half in length. These tails are of a substance between fat and marrow. A sheep of this kind weighs sixty or seventy English pounds weight, of which the tail usually weighs fifteen pounds and upwards. This species is by far the most numerous in Arabia, Syria, and Palestine, and, forming probably a large portion in the flocks of the Israelites, it seems to have been the kind that usually bled on the Jewish altars. The extraordinary size and deliciousness of their tails give additional importance to this law. To command by an express law the tail of a certain sheep to be offered in sacrifice to God, might well surprise us; but the wonder ceases, when we are told of those broad-tailed Eastern sheep, and of the extreme delicacy of that part which was so particularly specified in the statute [PAXTON].

JFB.