937 – Ibn ʿAbbās (may Allah be pleased with him) said, “If a man declares his wife unlawful to himself, it amounts to nothing,” and he recited, “Indeed, in the Messenger of Allah you have an excellent example.” Recorded by al-Bukhārī.
Muslim transmits from Ibn ʿAbbās: “When a man declares his wife unlawful to himself, that is an oath whose expiation is due.”⦗1⦘

What is taken from the ḥadith:
1 – The sense of the report is that when a husband says to his wife, “You are forbidden to me,” such a declaration is not a divorce; rather, it counts as an oath and therefore requires the expiation for oaths, as Allah says: “O Prophet, why do you prohibit what Allah has made lawful for you, seeking the approval of your wives? Allah is All-Forgiving, Most Merciful. Allah has already ordained for you a way to absolve your oaths” (Al-Taḥrīm 1–2). In other words, Allah has legislated that you dissolve your oaths by paying the expiation mentioned in Sūrat al-Māʾidah.
2 – The ḥadith indicates that if someone declares unlawful something Allah has made lawful for him, that thing does not in fact become unlawful, for the authority to declare things lawful or unlawful belongs solely to Allah. Hence His words: “O you who believe, do not prohibit the good things Allah has made lawful for you” (Al-Māʾidah 87). There is no difference between someone who permits what Allah has forbidden and one who forbids what Allah has permitted; both are encroachments upon Allah’s rulings.
3 – Ibn ʿAbbās’s statement is explicit: when a man declares his wife unlawful to himself, his declaration becomes an oath, and the expiation for oaths mentioned in Sūrat al-Māʾidah dissolves it.
In such an oath, it is obligatory for the oath-taker to carry out the very act he had declared forbidden and sworn about,