Kashrut כשרות
The laws of permitted food: which animals, how they are slaughtered, and the separation of meat from milk.
The first dietary restriction precedes Sinai: the sons of Noach are forbidden flesh taken from a living animal. The full system is given in Vayikra and Devarim: animals with split hooves that chew the cud, fish with fins and scales, listed birds; blood and certain fats forbidden.
To this is added shechita—slaughter by a trained shochet with a flawlessly smooth blade—and inspection of the organs. A separate strand grows from the thrice-repeated "do not cook a kid in its mother's milk", from which the Oral Torah derives the ban on cooking, eating or profiting from mixtures of meat and milk, and hence separate utensils and waiting times.
The Torah gives almost no reason, saying only "be holy". The Rambam looked for medical sense in it; the Ramban insisted the point is the discipline of choice.
On the timeline
Related
Sources
Tanakh
- Vayikra 11 — the signs of the permitted animals
- Devarim 14 — the repetition of the list of permitted foods
- Shemot 23:19 — “do not cook a kid” — the root of the separation of meat and milk
Chazal: Mishnah, Talmud, midrash, Zohar
- Chullin 103b — the analysis of the prohibition of meat with milk
Acharonim and later rabbinic literature
- Shulchan Aruch, Yoreh Deah 1–111 — the laws of kashrut in the code
Basis: tradition.