• The noble verse shows that when a person declares something lawful—food, drink, clothing, personal use, a bond-woman, and the like—to be forbidden to himself, his mere declaration does not in fact make the lawful unlawful. Yet if he goes on to break that self-imposed ban, he must pay the expiation for an oath, because such a declaration counts as an oath. Allah the Exalted says: “O Prophet, why do you prohibit what Allah has made lawful for you, seeking to please your wives? Allah is All-Forgiving, Most Merciful. Allah has already ordained for you the dissolution of your oaths” (66:1-2).
This applies to forbidding any wholesome thing, except that declaring one’s wife forbidden constitutes ẓihār, for which the previously mentioned expiation for ẓihār is required.
Just as a person is not allowed to swear that he will abandon wholesome things, he is likewise not permitted to abstain from them without an oath out of asceticism or excessive rigor in religion; rather, he should partake of them, using them as an aid in obeying his Lord.

• “Allah will not call you to account for idle words in your oaths” (5:89). This includes oaths uttered without intention or deliberation, or sworn under the assumption that one is speaking the truth only to discover the contrary.

• “But He will call you to account for those oaths you bind deliberately”⁠—that is, for what your hearts have firmly resolved upon, as He says in another verse: “but He will call you to account for what your hearts have earned” (2:225).

• When a servant intentionally binds an oath and then breaks it—by doing what he had sworn to leave or by leaving what he had sworn to do—he may choose for expiation among:

• “Feeding ten needy people with the average of what you feed your own families” (5:89). The exact amount varies with people, times, and places.

• “Or clothing them” with garments regarded as proper clothing, specified as an outfit that would be acceptable for performing the prayer.