What is the ruling regarding a husband telling his wife: "You are a man, not a woman," with the intention of ending a discussion, and is it permissible for him to say such words?

A husband must treat his wife well, according to the Almighty's saying, "And live with them in kindness." This includes fulfilling her rights, avoiding harming her with harsh words or frowning at her without cause. Likening the wife to a man is a sign of ill-treatment. One should beware of anger and address it with what is mentioned in the Sunnah.