Why does a man have intercourse with his wife in her vagina and not in her anus?

Metaphorical language should be used for matters that cause embarrassment, and explicit language should only be used when necessary for a legitimate religious purpose. A woman should be approached in her front, in obedience to Allah's saying: "So approach them from where Allah has commanded you," and to the Prophet's (peace be upon him) saying: "Approach from front and back, but beware of the anus and menstruation." She should not be approached in her anus, because the one who does so is cursed. The evils of anal intercourse are numerous: it is a place of constant harm, it risks the cessation of progeny, it deprives the wife of her right and does not fulfill her purpose, it was not prepared for this act, and it harms the man because it is against nature and causes strain. For these reasons, doctors forbid it.