basar b'chalav (To those whom speak Lashon Hara)

[rabbicummings]

Separation of Meat and Dairy
On three separate occasions, the Torah tells us not to "boil a kid in its mother's milk." (Ex. 23:19; Ex. 34:26; Deut. 14:21). The Oral Torah explains that this passage prohibits eating meat and dairy together. The rabbis extended this prohibition to include not eating milk and poultry together. In addition, the Talmud prohibits cooking meat and fish together or serving them on the same plates, because it is considered to be unhealthy. It is, however, permissible to eat fish and dairy together, and it is quite common (lox and cream cheese, for example). It is also permissible to eat dairy and eggs together. This separation includes not only the foods themselves, but the utensils, pots and pans with which they are cooked, the plates and flatware from which they are eaten, the dishwashers or dishpans in which they are cleaned, the sponges with which they are cleaned and the towels with which they are dried. A kosher household will have at least two sets of pots, pans and dishes: one for meat and one for dairy.

Since the Book of Genesis refers to young goats by the Hebrew phrase g'di izim, but the prohibition against boiling a kid... only uses the term g'di, Rashi concluded that the term g'di actually has a more general meaning, including calves and lambs, in addition to young goats. Rashi also implies that the meaning of g'di is still narrow enough to exclude birds. The Talmudic writers had a similar analysis, but believed that since domesticated kosher animals (sheep, goats, and cattle) have similar meat to birds and to the non-domestic kosher land-animals, they should prohibit these latter meats too, creating a general prohibition against mixing milk & meat from any kosher animal, except fish. Rashi expressed that the reference to mother's milk must exclude fowl (birds) from the regulation, since only mammals produce milk. Substances derived from milk, such as cheese and whey also fall under this prohibition, but milk substitutes, created from non-dairy sources, do not.