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.
Is it permissible for a sick person to pray while sitting on a chair?
All perfect praise be to Allah, The Lord of the Worlds It is permissible for a sick person, who is unable to stand up, to offer prayer while sitting on a chair. If he/she was unable to prostrate while on the chair, the he/she should pray while sitting on the ground, but if he/she was neither able to bow (Roku),nor to prostrate, then he can do them while sitting on the chair. And Allah Knows Best.
What is the ruling on one who vows to fast a specific or non-specific year? Are the two Eids, the days of Tashreeq, Ramadan, and the days of menstruation and postnatal bleeding included in them? And do these days break the consecutiveness if it was intended?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
If someone makes a vow (Nadr) to fast a specific, designated year, this vow does not include the days of Eid, the days of Tashreeq (the three days following Eid al-Adha), Ramadan, or the days of menstruation (Hayd) and postnatal bleeding (Nifas). Furthermore, there is no requirement to make up (Qada) these specific days.
However, if someone vows to fast a year that is not specifically designated (i.e., any twelve-month period) and stipulates that the fasting must be consecutive, they are bound by that condition. They must not fast on the days of Eid, during Ramadan, or during menstruation, but they are required to make up these days afterward—with the exception of the days of menstruation and postnatal bleeding, which do not need to be made up.
It is stated in Hashiyat al-Bajuri ‘ala Sharh Ibn Qasim ({Vol.2/P.606): 'If one vows to fast a specific year, the Eid, Tashreeq, Ramadan, and days of menstruation or postnatal bleeding are not included. This is because Ramadan does not accept any fast other than its own, and the others do not accept fasting at all. Therefore, they do not enter into the vow, and no makeup is required for them because they are legally excluded—contrary to Al-Rafi’i regarding menstruation and postnatal bleeding.
If one vows to fast a non-designated year: if they stipulated consecutiveness (Tatuabu’) in their vow, they must fulfill it; otherwise, they are not bound to it. Consecutiveness is not broken by the days that do not enter into the specific year vow (Eid, Tashreeq, Ramadan, menstruation, and postnatal bleeding). However, one must make up the days missed—excluding the time of menstruation and postnatal bleeding—immediately following the end of the year. As for the time of menstruation and postnatal bleeding, it is not made up, contrary to Ibn al-Rif’ah, who argued that it must be made up just like Ramadan.' And Allah the Exalted knows best.
What is the ruling on performing the standing (qiyām) and bowing (rukū‘) portions of the prayer normally, while performing the prostration (sujūd) seated due to knee pain?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
If performing sujūd (prostration) in prayer causes the worshipper pain in the knees, then it is permissible for him to perform it through gesture (īmā') while seated, since Allah, Glorified and Exalted is He, has lifted hardship from His servants. On the authority of ‘Imrān ibn Ḥuṣayn (raḍiyallāhu ‘anh), he said: "I suffered from hemorrhoids, so I asked the Prophet ﷺ about [how to perform] the prayer, and he said: 'Pray standing; if you are unable, then sitting; and if you are unable, then on your side.'" [Ṣaḥīḥ al-Bukhārī]
If the valid excuse later subsides, the worshipper is then obligated to perform the prayer with all its pillars and conditions fully observed — including standing, rukū‘ (bowing), and sujūd (prostration). And Allah, the Exalted, knows best.