Explanation of biblical law
The rabbis of the Talmud gave no reason for the prohibition, but later authorities, such as Maimonides, opined that the law was connected to a prohibition of Idolatry in Judaism. Obadiah Sforno and Solomon Luntschitz, rabbinic commentators living in the latemiddle ages, both suggested that the law referred to a specific foreign religious practice, in which young goats were cooked in their own mothers' milk, aiming to obtain supernatural assistance to increase the yield of their flocks. More recently, a theogonous text, named the birth of the gracious gods, found during the rediscovery of Ugarit, clarified that a Levantine ritual to ensureagricultural fertility involved the cooking of a young goat in its mother's milk, followed by the mixture being sprinkled upon the fields. Another explanation is the separation accommodates significantly the large percentage of the population, particularly those who are aging, who are lactose intolerant.
The biblical suppression of these practices was seen by some rabbinic commentators as having an ethical aspect. Sforno argued that using the milk of an animal to cook its offspring was inhumane, based on a principle similar to that of Shiluach haken, the injunction against gathering eggs from a nest while the mother bird watches. Chaim ibn Attar compared the practice of cooking of animals in their mother's milk to the barbaric slaying of nursing infants.