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 congregational prayer performed outside the mosque, and is it a condition that it be performed in a mosque in order to attain the full reward?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
It is not a condition for attaining the reward of congregational prayer that it be performed in a mosque; however, a Muslim should still be keen to perform his prayers in the mosque, so as not to miss out on immense reward. This is due to the virtue of the mosque and of spending time there (i‘tikāf), the typically larger number of worshippers present, and the additional reward gained through walking to and from the mosque. On the authority of Abū Hurayrah (raḍiyallāhu ‘anh), the Messenger of Allah ﷺ said: "Whoever purifies himself in his house, then walks to one of the houses of Allah to fulfill one of the obligations Allah has prescribed, one of his steps will erase a sin, and the other will raise him a degree [in status]." (Related by Muslim)
Whoever misses congregational prayer at the mosque should still strive to pray in congregation at his workplace, or together with the members of his household. And Allah, the Exalted, knows best.
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.