What is the ruling on mentioning Allah`s name upon slaughtering an animal?
Praise be to Allah, and peace and blessings be upon our master, the Messenger of Allah.
It is Sunnah for the slaughterer to say at the time of sacrificing the Udhiyah: (Bismillah - In the name of Allah); due to the saying of the Almighty: "So eat of that [meat] upon which the name of Allah has been mentioned" [Al-An'am/118]. It is not obligatory; if one leaves it out intentionally or forgetfully, the consumption of the meat remains permissible. And Allah the Almighty knows best.
What are the key differences between the 'aqīqah and the uḍḥiyyah?
All praise is due to Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
The following are the key differences between the 'aqīqah and the uḍḥiyyah:
First: The 'aqīqah is slaughtered as an act of drawing closer to Allah the Almighty and expressing gratitude for the blessing of a newborn child. The uḍḥiyyah, on the other hand, is slaughtered as an act of drawing closer to Allah and expressing gratitude to Him specifically during the days of slaughter (ayyām al-naḥr).
Second: The 'aqīqah is performed on the seventh day from the birth of the newborn, whereas the uḍḥiyyah is performed on Eid al-Aḍḥā and its time extends for three days after the Eid.
Third: The 'aqīqah is performed once in a lifetime for the newborn, whereas the uḍḥiyyah is recommended every year.
Fourth: It is Sunnah for the one intending to offer the uḍḥiyyah to refrain from cutting his hair and nails until after he has slaughtered. This is not a Sunnah for the one intending to perform the 'aqīqah.
Fifth: It is Sunnah for the 'aqīqah to be cooked and distributed to the poor in its cooked form. The uḍḥiyyah, by contrast, must be distributed as raw meat. And Allah Almighty knows best.
Is it a condition for I‘tikaf to be performed in the mosque?
Yes, for I‘tikaf to be valid, it must be performed in a mosque. I‘tikaf is not valid if performed at home or elsewhere.
Is it incumbent on the fiancée to obey her fiancé?
When the woman settles in her husband`s house, it is incumbent on him to provide for her and it is incumbent on her to obey him. Before that, and if the marriage contract had been concluded, then she is lawfully his wife and thus she should abide by custom in treating him, but if the marriage contract hadn`t been concluded, then she should treat him as a non-Mahram (Marriageable).