What is the way to repent from swearing by the prohibition of one's religion, such as saying, "It is forbidden upon my religion that I do not do such-and-such," while wishing to do the thing sworn upon, and what is the sacredness of this oath?

If a person says, "What is lawful is unlawful for me," intending not to do a specific act, and then does it, an expiation for breaking an oath (kaffarat yamin) is incumbent upon him. And if he performs the expiation for ẓihār (a form of divorce by injurious utterance), it is better. The expiation for breaking an oath is feeding ten poor people, or clothing them, or freeing a slave. If he is unable to do so, then fasting for three days. The expiation for ẓihār is freeing a slave. If he cannot find one, then fasting for two consecutive months. If he is unable to do that, then feeding sixty poor people. Swearing by other than Allah is minor shirk. Therefore, a Muslim should accustom his tongue to not swearing oaths, but if he needs to, he should swear by Allah or by one of His attributes. If he swears by other than Allah, he must say, "There is no god but Allah."