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.
Where should a woman following her husband or another man in prayer stand?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
If a single woman prays with a man—whether she is his wife or a non-mahram (Ajnabiyyah)—the Sunnah is for her to stand behind the Imam and be shielded by him. If the Imam is leading both a man and a woman, the man should stand to the Imam's right, and the woman should stand behind the male follower (Muqtadi). In this way, she is shielded from the Imam by the male follower and remains at a distance from the follower and his line of sight. And Allah the Exalted knows best.
What is the ruling of Islamic Law on selling gold or silver in installments or for a differed price?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
It is prohibited (haram) to sell gold or silver in installments or for a deferred price; rather, immediate hand-to-hand exchange (Taqabud) is mandatory, otherwise, it is considered usury (Riba). The Messenger of Allah ﷺ said: 'Gold for gold, silver for silver, wheat for wheat, barley for barley, dates for dates, and salt for salt—like for like, hand to hand. Whoever increases or asks for an increase has engaged in Riba; the receiver and the giver are the same in this regard.' (Narrated by Muslim). Furthermore, when exchanging new gold for used gold, they must be of equal weight, or it falls into Riba.
The permissible solution (al-makhraj) is for the merchant to purchase the used gold for cash first, and then sell the new gold for cash in a separate transaction. However, the price must be paid during the sitting of the contract (Majlis al-Aqd) for both deals. Alternatively, the jeweler may take the used gold with the intent of remodeling or repairing it, and then charge a fee for the craftsmanship or repair work. And Allah the Exalted knows best."
Which takes precedence: the 'aqīqah or the uḍḥiyyah?
All praise is due to Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
The 'aqīqah is an act of worship through which a servant draws closer to Allah the Almighty in gratitude for the blessing of a newborn child. It is a confirmed Sunnah for those who are financially capable, and Allah does not burden any soul beyond what it can bear.
However, the uḍḥiyyah takes precedence, as it is a confirmed Sunnah established from the Prophet ﷺ through stronger and more numerous narrations — indeed, the Ḥanafī scholars hold it to be obligatory. Furthermore, its time is narrow and limited, expiring with the passing of the days of Eid, whereas the 'aqīqah may be delayed until one becomes financially capable of performing it.
And Allah Almighty knows best.