Is Fajr (dawn) Sunnah a confirmed one?
All praise be to Allah The Lord of The Worlds Of course, it is a confirmed Sunna which the Prophet (PBUH) used to offer in a regular basis. And Allah Knows Best.
Is the prayer of someone who didn`t face Quibla (Ka`ba direction) valid?
All perfect praise be to Allah,The Lord of The Worlds. Facing the Quibla is a condition for the validity of prayer, and the prayer of the person who hadn`t faced the direction of the Quibla is invalid, and he is obliged to repeat it. And Allah Knows Best.
Is it permissible for the father to give the Zakat of his money to his poor married son?
It is permissible for the father to give part of the Zakat to his poor son, if the latter was sound and healthy, because in this case the father isn't obliged to spend on his young son, even though; he is considered one of the Muslims poor. And Allah Knows Best.
My husband wanted to sell a piece of land that was his own, but his father insisted that he transfer the land in his (the father’s) name so that he could sell it at a higher price. Then, my husband and his father would split the price. After my father-in-law sold the land, he denied everything and refused to acknowledge my husband’s right. My father-in-law passed away a year ago, and my husband’s brothers divided the inheritance, refusing to acknowledge that this land was a trust held by their father for my husband until it was sold. Are they sinful for knowingly denying that the land belongs to my husband, and what is the ruling on praying against them?
All perfect praise be to Alalh, The Lord of The Worlds, and may His Peace and Blessings be upon our Prophet Muhammad and upon all of his family and companions.
Among the rights of the deceased upon their heirs are: preparing them for burial at death, settling their debts, returning people’s rights to them, executing their will, and then dividing their estate. What was mentioned in the question falls under the rights of others, even if they are among the heirs, and the deceased is not absolved of it unless it is returned to its rightful owners. This is because Allah, Almighty, forbids consuming others' wealth/properties unjustly. However, do not give up on seeking a solution by involving righteous and well - respected individuals who may have influence over them, in the hope that Allah guides them to goodness and correctness. As for supplicating against them, the prayer of the oppressed is not rejected, even if the oppressed person is not a Muslim. And Allah knows best.
