I want to buy a house by having a loan from a bank?
If taking a loan from usrious banks it is impermissible; on the other hand, if this took place through Islamic ones then it is permissible to get the loan, since Allah the Most Exalted Said (What means): "And Allah has made buying lawful and forbidden usury (riba)." And Allah Knows Best.
Is a woman`s prayer considered invalid if non-Mahrams (marriageable men) saw her offering it?
A woman`s prayer isn`t invalidated if non-Mahrams saw her offering it, but she had better pray in isolation.
I am an author, and I have books stored with me. Is it permissible to pay my zakat in the form of books containing beneficial knowledge for poor students, such as chemistry and mathematics, or religious books that spread Islamic sciences?
Zakat on wealth must be paid in cash from the wealth itself. Therefore, you should pay your zakat in monetary form so that the poor can purchase what they need. And Allah Knows Best.
I have a question regarding the deferred portion of the dowry (Mahr)*. Is the wife entitled to it only upon divorce or she can claim it even if divorce hasn`t taken place? Moreover, does she have the right to claim this portion after death of husband, even if he didn`t divorce her before that?
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.
In the marriage contract, it is recorded that the deferred portion of the dowry is due upon divorce or death, whatever comes first. If divorce took place first then the woman is entitled to it and if the husband died this amount must be paid from his estate. On the other hand, if the woman died then the husband becomes liable for this portion and it becomes part of the woman`s estate. We advise every husband to give this portion to his wife while alive because it is a right of hers. And Allah The Almighty Knows Best.
* In Islam, a Mahr is the obligation, in the form of money or possessions paid by the groom, to the bride at the time of Islamic marriage (payment also has circumstances on when and how to pay). While the mahr is often money, it can also be anything agreed upon by the bride such as jewelry, home goods, furniture, a dwelling or some land. Mahr is typically specified in the marriage contract signed upon marriage.
