A man taking an oath not to marry his cousin, then he marries her

Q: A person's mother asked him to marry his cousin, but he took an oath not to marry her. Then, he married her. He is asking about (Part No. 20; Page No. 115) the consequences of the oath he took?

A: If the reality is as mentioned; that he swore an oath not to marry his cousin then he married her, he will be considered as having broken his oath. Accordingly, he is required to offer Kaffarah (expiation) for an oath, which is to emancipate a believing slave, feed ten Miskins (needy persons) - each one half a Sa` (1 Sa`=3 kg. Approx.) from the staple food of the country, or provide them with clothing. If he cannot afford any of these, he must observe Sawm (Fast) for three days. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.