The Jewish dietary laws -- kashrut -- constitute the oldest continuously practiced system of bodily regulation in the Western world. The laws are codified primarily in Leviticus 11 and Deuteronomy 14, with extensive elaboration in the Talmudic and post-Talmudic rabbinical literature. The system specifies which animals may be consumed (land animals that both chew their cud and have split hooves; fish with both fins and scales; specific categories of birds), how they must be slaughtered (shechita, a single uninterrupted cut across the trachea and esophagus with a perfectly sharp blade), how meat and dairy must be separated (in preparation, consumption, and utensils), and how blood must be removed from meat before consumption.
The conventional interpretation -- that kashrut represents primitive health regulation, an attempt to avoid trichinosis or food-borne illness -- was definitively challenged by Mary Douglas in Purity and Danger (1966). Douglas demonstrated that the dietary prohibitions follow a logic of classification rather than hygiene. Animals that violate their category -- the pig, which has a split hoof but does not chew its cud; shellfish, which inhabit water but lack the defining features of fish -- are prohibited not because they are dangerous but because they are anomalous. They cross boundaries. The dietary system, Douglas argued, mirrors the social and cosmological system: it maintains the integrity of categories that order the world. The body of the worshiper becomes analogous to the sanctuary -- a bounded space whose integrity must be maintained against what would disorder it.
Islamic halal and haram regulations share structural features with kashrut while operating within a distinct theological framework. The Quran specifies prohibited categories (carrion, blood, pork, animals slaughtered without invoking God's name) in Surah Al-Baqarah (2:173) and Surah Al-Ma'idah (5:3). The concept of tayyib -- good, wholesome, pure -- extends beyond mere permissibility to a positive requirement that food be nourishing, clean, and obtained through ethical means. The halal certification system that developed to operationalize these requirements represents an institutional infrastructure for bodily protection: a system of inspection, certification, and enforcement that maintains the boundary between what enters the body and the commercial food supply that would otherwise determine that boundary unilaterally.
What kashrut and halal share, beneath their theological and legal differences, is a structural function: they interpose a system of communal regulation between the individual body and the external food supply. The individual does not simply consume what is commercially available. The community maintains standards -- of sourcing, preparation, classification, and quality -- that the individual body can rely on. The body's intake is governed by a collective intelligence rather than by the commercial interests of food producers. This is bodily protection in its most literal form: the protection of the body's biological inputs from capture by commercial systems optimizing for profit rather than biological flourishing.