Rav Avigdor Miller on The Sin of Smoking
Q:
Is it against the Torah to start smoking?

A:
The Alter of Slabodka was once asked, what’s the first mitzvah of the Torah? So he said – he said it in litvish: Nebuk dur nisht – “Don’t be a fool.” That’s the first commandment of the Torah – don’t be a fool. Anybody who’s a fool is a choiteh.

If a person starts fooling around with drugs, he’s a sinner – a very big choteih. So you’ll say what did he do wrong? Where does it say that drugs are ossur? It’s a glatt kosher drug; he’s not eating treif. What of it?

What of it?! It’s a glatt kosher funeral. A man jumps off a roof and he says it’s glatt kosher to jump off a roof. It’s as ossur as could be. ושמרתם את נפשותיכם – Hashem says, “I’m lending you your body. It’s not your body – I’m lending it.” And a sho’el is chayav b’onsim. If you borrow something you have to pay for whatever goes wrong. Let’s say if I lend you a watch, so now you have to guard my watch. You can’t throw it around. “I’ll lend you the body,” says Hashem, “so you have to guard it.”

Now, here’s a person who start smoking; he takes a pack. On the package it says, if you start smoking, you should know it can be dangerous for your lungs, emphysema, cancer and so on. And this meshuganer lights a cigarette. So Hashem says “Look, it’s a mitzvah to have some common sense. You don’t have common sense – therefore you’re a very great choiteh.” And therefore anybody who smokes is a very great choiteh.