it, unless it be carrion, or blood poured forth, or the flesh of swine—for indeed, it is impure.” That is, unless the thing forbidden to the one who eats it is “carrion, or blood poured forth, or the flesh of swine—for indeed, it,” meaning that thing, “is impure”; that is, ritually impure.

If someone were to say: The prohibition of what is impure is clear, since it is intrinsically impure. Every impure substance is forbidden, though not everything forbidden is impure. This principle has already been discussed in the chapter on vessels. (1) But what is the evidence that something contaminated by impurity is forbidden?

The answer is that something contaminated by impurity has been affected by it and mixed with it; the impurity remains in it. Thus, if you eat or drink it, you have come into direct contact with impurity—you have eaten and drunk impurity. For this reason, we say that whatever is contaminated by impurity is forbidden, because it is not pure. If the Sacred Law commands us to remove impurity from the outward surfaces of our bodies, then how could we bring impurity into the insides of our bodies?!

His words, “contains no harm,” exclude that which is pure but harmful. Whatever is pure yet harmful is not permissible; rather, it is forbidden, whether the harm lies in the substance itself or arises from something else.

An example of harm inherent in the substance itself is poison: its harm lies in the substance itself. The same applies to tobacco, for it is harmful in itself. Its harmfulness is unanimously acknowledged by physicians today; no two of them disagree about it, due to the poisonous substances it contains that damage the blood.

As for what is harmful due to something else, this is like a food that is incompatible with another food: meaning that, if you combine the two foods, harm results; but if