What is the Du`a (supplication) of Istikhara (guidance prayer)?
O Allah, I consult You as You are All-Knowing and I appeal to You to give me power as You are Omnipotent, I ask You for Your great favor, for You have power and I do not, and You know all of the hidden matters. O Allah! If you know that this matter (then he should mention it) is good for me in my religion, my livelihood, and for my life in the Hereafter, or he said: "for my present and future life" then make it (easy) for me. And if you know that this matter is not good for me in my religion, my livelihood and my life in the Hereafter, or he said: "for my present and future life" then keep it away from me and take me away from it and choose what is good for me wherever it is and please me with it."
Is it permissible for a wife to refuse to go to bed with her husband (for sexual intercourse)?
It isn`t permissible for her to do so unless for a sound reason.
A man married a woman at the Islamic Centre in Brussels through a regular marriage contract. However, the husband left her for two years now and never provided her with financial support. Currently, she is staying in Amman, Jordan, and wants to remarry. Is her first marriage considered void and what should she do to remarry lawfully?
All perfect praise be to Allah, the Lord of the Worlds; may His blessings and peace be upon our Prophet Mohammad and upon all his family and companions.
This issue is within the jurisdiction of the Islamic courts and they have the final say regarding the dissolution of the first marriage contract if there is valid ground for that. Therefore, her first marriage remains valid unless a court decision says otherwise. And Allah The Almighty Knows Best.
Is it permissible for one to masturbate in order not to commit fornication?
This is called committing the milder of the two evils such as eating a carcass in fear of death, and this happens when committing fornication is very likely to occur.