What is the ruling regarding someone who made a promise to Allah, covenanted, and swore to abandon a sin or perform an act, then failed to fulfill it? Is expiation (kaffarah) obligatory upon him, even if delayed? Is it permissible for him to fast three days instead of feeding or clothing (the needy)? And are a promise, covenant, and oath considered valid by intention without verbalization?

If a person says, "I covenant with Allah to do such-and-such," then if the commitment is an act of devotion and obedience, it is both a vow (nadhr) and an oath (yamin), as Allah Almighty says: "And among them are those who covenanted with Allah, 'If He should give us from His bounty, we will surely spend in charity, and we will surely be among the righteous.'" (Quran 9:75). If it is not an act of devotion, then it is only an oath, such as saying, "I covenant with Allah not to speak to so-and-so." As for swearing by Allah Almighty not to do something, it is an explicit oath, and expiation is required upon breaking it. This expiation is feeding ten poor persons or clothing them, or freeing a slave. If one cannot find these, then fasting for three days. An oath, a vow, and a covenant do not come into effect by mere intention without utterance; mere self-talk does not entail anything.