Vowing to visit the grave of Prophet Shu`ayb if granted a child

Q: My maternal uncle is Palestinian, but he lives in Lebanon. His home city is `Akka in the occupied territories. He has been married for twenty five years, and two years ago his wife gave birth to a baby girl. My question is: Before having a child, my uncle vowed to visit the sepulcher of Prophet Shu`ayb if Allah (Glorified and Exalted be He) blessed him with a child, male or female. This sepulcher is in the occupied territories in Palestine; it is regarded as a shrine and is visited by the people of the region. Reaching this place has become very difficult, as my uncle is in Lebanon and not permitted to go to Palestine. What is the view of Your Honor, should he fulfill his vow no matter how difficult, or can he make Kaffarah (expiation) for breaking it by feeding needy persons or fasting? I know that we should not set out on a journey except for three Mosques, i.e. Al-Haram-ul-Makky (the Sacred Mosque in Makkah), Al-Masjid Al-Nabawy and Al-Aqsa Mosque (in Jerusalem). (Part No. 23; Page No. 236

A: If the case is as you have mentioned, it is Haram (prohibited) to fulfill his vow, for it is a vow to perform an act of disobedience. Vowing is in itself an act of worship that should solely be devoted to Allah. He must repent to Allah and ask His Forgiveness. He should not repeat this and should regret what he has done.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.