Hadiths on Zihaar (Likening one's wife to an unmarrriagble woman)

This section gathers 3 hadiths on the zihaar, the formula by which a man declares his wife as forbidden to him as his mother, his sister or his aunt: Ibn Abbas taught that such a declaration "is nothing", the Messenger of Allah remaining the excellent example to follow; the case of the man who uttered this formula and then had intercourse with his wife; and the hadith of Salamah ibn Sakhr about the oath of abstinence. One hadith is authentic, two are good.