Swearing that one's wife will be unlawful for him if his son entered a certain Masjid

Q: I live in an Egyptian village. Once I had an argument with my father about visiting and touching the graves of Awliya' (pious people) with veneration. He knows that I go to a specific Masjid (mosque) in our village where most of the people who frequent it do not adopt such deviating beliefs. When I tried to forbid him from what he is doing, he took an oath that I should not enter this Masjid again. He said, "If you enter this Masjid, your mother will be unlawful for me." I care for my brothers and I do not want to ruin the family by breaking this conditional oath. Nevertheless, I want to offer Salah (Prayer) behind an Imam (the one who leads congregational Prayer) who adheres to the principles of Tawhid (monotheism), because I am keen to enter Jannah (Paradise) and I know the prohibition of offering Salah behind those who excessively esteem the graves of righteous people. Will my mother be divorced if I enter this Masjid? If it is considered Zhihar (a man likening his wife to an unmarriageable relative) and I ask my father to offer Kaffarah (expiation) so that I will be able to enter the Masjid, will it be considered as precipitating something destined by Allah (Exalted be He); ruining the family? If it is Zhihar, will I be allowed to offer the Kaffarah from my father's money without his knowledge? What should I do? Please answer me in detail, simply and quickly. As-salamu `alaykum warahmatullah wabarakatuh (May Allah's Peace, Mercy, and Blessings be upon you).

A: If your father's intention when taking the oath was Talaq (divorce pronounced by a husband), entering this Masjid would make your mother's Talaq effective. In this case, your father can take her back in marriage as long as she is still in her `Iddah (woman's prescribed waiting period after divorce) and this is not the third time of Talaq. (Part No. 20; Page No. 105) If your father's intention when taking the oath was to prevent you from going to this Masjid and not Talaq, entering the Masjid would not result in Talaq. However, your father has to offer Kaffarah for his oath, which is emancipating a believing slave, or feeding ten needy persons, or providing them with clothing. If he cannot do any of these, he should observe Sawm (Fast) for three days. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.