Is the niṣāb calculated based on the price of 21-karat gold, or 24-karat gold?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
Zakāh is obligatory on cash and on gold designated for saving or for trade, provided the total reaches the niṣāb (minimum threshold liable for zakah), and a full ḥawl (lunar year) has elapsed over it. The niṣāb is (85) grams of 24-karat gold; for 21-karat gold, the niṣāb equals (97) grams; and for 18-karat gold, it equals (113) grams.
The relied-upon position is to calculate the zakāh based on the buying price [i.e., the price the gold merchant would pay the owner to purchase the gold from him] on the day the zakāh obligation is due.
The one paying zakāh may assess/calculate the niṣāb using any of the aforementioned gold karats [i.e., he may choose whichever karat standard he wishes for the purpose of the calculation]. And Allah, the Exalted, knows best.
What is the difference between Qiyam al-Layl and Tahajjud?
● Qiyam al-Layl refers to any voluntary prayer performed at night, including Tarawih.
● Tahajjud specifically refers to voluntary prayer performed at night after waking up from sleep.
Glad tidings to those who combine both, as numerous Quranic verses and hadiths mention their virtues.
Allah Almighty says {what means}: "And rise from thy sleep and pray during part of the night [as well], as a free offering from thee, and thy Sustainer may well raise thee to a glorious station [in the life to come." [Al-Isra`/79]
The Prophetﷺ said: "Whoever stands (in prayer) during Ramadan with faith and seeking reward, all their past sins will be forgiven." [Agreed upon]
What is the ruling on swearing on the Holy Quran and breaking that oath?
It is impermissible to swear on the Holy Quran in vain, and it is also impermissible to subject it to such an act since breaking the oath after swearing on the Quran entails an expiation.
Is bleeding that lasts for nine or ten days considered menstruation (Hayd)?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
If the duration of the bleeding does not exceed fifteen days, then all of it is considered menstruation (Hayd), even if the regular cycle ('Adah) has changed. And Allah the Exalted knows best.