What is the ruling on one who promised God not to commit a forbidden act, then returned to committing it, and swore by the Qur’an three times not to commit it, then committed it? Is there an expiation for that, and what is it? And is fasting waived for pregnant or postpartum women?

Expiation for sins is achieved through sincere repentance, remorse, increased good deeds, and seeking forgiveness. As for the expiation for an oath (kaffarat al-yamin), before fasting, one must either free a slave, or feed ten needy people, or clothe them. If you are unable to do that, then you must fast for three days. If you are unable to fast due to fear for the fetus, then there is no objection to delaying it until you are able.