How is the niṣāb (minimum threshold) of gold calculated when one owns gold of multiple different karats?
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.
If one owns gold of multiple different karats, the person paying zakāh should calculate the monetary value of all the gold he owns, combining these values together to determine whether the total reaches the niṣāb. He then pays zakāh on this combined monetary value, once the total reaches the niṣāb. 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. And Allah, the Exalted, knows best.
Is it permissible for a pious Muslim woman to stay with her husband who had quit praying out of laziness?
Quitting prayer is one of the major grave sins that come after disbelieving in Allah, but the wife of such a person isn`t considered divorced, rather, she should exert all her efforts in order to bring him back to the way of Islam. However, if his sin is likely to lure her from the way of Islam, then she had better separate from him by lawful means such as Mokhal`aa (When a wife pays a compensation for her husband in return for divorcing her). Moreover, if she exercises patience, and remains steadfast on her faith, then there is no harm in doing that.
Is it permissible to include others in the reward of one`s sacrifice?
In the Name of Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
It is permissible for the person offering an Udhiyah (sacrificial offering) to include others in the spiritual reward of the sacrifice. However, it is not permissible for multiple people to jointly share the purchase price of a single sheep or goat, unless one person gifts the money to the other.
It is stated in Mughni al-Muhtaj (6/137) by Al-Khatib al-Shirbini:
"If a person includes someone else in the reward of his sacrifice and slaughters it on his own behalf, it is permissible."
It should be carefully noted that including someone else in the reward of one's sacrifice is completely distinct from offering a sacrifice on behalf of someone else. And Allah the Almighty Knows Best.
A man led the people in prayer as imam, and at the end of the prayer he performed a prostration of forgetfulness (*sujūd al-sahw*) because he had omitted a short *sūrah* after al-Fātiḥah. What is the ruling on his prayer and that of those praying behind him?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
According to the Shāfiʿī school, it is sunnah to recite a sūrah after al-Fātiḥah in the prayer. One who omits it has a valid prayer, and no prostration of forgetfulness (sujūd al-sahw) is prescribed for omitting it. If someone performs sujūd al-sahw for its omission while knowing the ruling and remembering it, his prayer is invalidated. But one who is ignorant of the ruling, or who did so out of forgetfulness, his prayer is not invalidated, because this is among the matters that are obscure to people, and ignorance of it is not restricted to those who recently entered Islam.
Shaykh al-Islām al-Shams al-Ramlī said in Nihāyat al-Muḥtāj ilā Sharḥ al-Minhāj (Vol.2/p.70): “The remaining sunnahs are not compensated for by prostration, such as the remembrances (adhkār) of bowing and prostration, that is, the opening supplication (duʿāʾ al-iftitāḥ) and the sūrah, in accordance with the base rule, because they are not of the same nature as what has been reported [as compensable]. If one prostrates for any of them deliberately, his prayer is invalidated, unless he is excused due to ignorance. As for the objection raised that the ignorant person does not know that sujūd al-sahw is prescribed, and whoever knows it knows its place, this is refuted by denying such a necessary connection, for the ignorant person may hear only that sujūd al-sahw is prescribed before the salām, and so assume that it applies to every sunnah and is not restricted to its prescribed place.”
This is among the matters that are obscure, in which the mukallaf is excused for ignorance, as stated by al-Shabrāmallisī in his Ḥāshiyah ʿalā Nihāyat al-Muḥtāj (Vol.2/p.70).
However, if the imam prostrates, and the follower (maʾmūm) presumes that his imam’s prostration is for a reason for which one does not prostrate, it is not permissible to follow him in it, so long as the follower knows the ruling.
Accordingly, the prayer of one who did not recite a sūrah after al-Fātiḥah is valid, and sujūd al-sahw is not prescribed for it. Whoever prostrates out of ignorance or forgetfulness, his prayer is valid, because this is among the issues hidden from the general public. But whoever prostrates while knowing the ruling and remembering it, his prayer is invalidated. And Allah Almighty knows best.