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 are the Sunnahs and etiquettes recommended for the person offering the Udhiyah?
In the Name of Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
There are several Sunnahs (prophetic traditions) and etiquettes that are highly recommended for the person offering an Udhiyah (sacrificial offering) to observe:
First:
It is a Sunnah for anyone intending to offer a sacrifice to refrain from cutting or removing any of their hair or nails once the first ten days of Dhul-Hijjah begin. This is based on the statement of the Prophet (peace and blessings be upon him): "When the ten days [of Dhul-Hijjah] begin and one of you intends to offer a sacrifice, let him not touch any of his hair or skin." (Narrated by Muslim)
However, if someone does happen to remove any hair or nails, they have not committed a sin, and their sacrifice remains perfectly valid.
Second:
The person offering the sacrifice should ideally slaughter the animal themselves. If they are unable to do so, they should at least witness its slaughter. This is drawn from what our Master, the Messenger of Allah (peace and blessings be upon him), said to Lady Fatima (may Allah be pleased with her):
"Stand up and witness your sacrifice, for with its very first drop of blood, every sin you have committed will be forgiven." (Narrated by Al-Tabarani in his Mu'jam, Al-Hakim in his Mustadrak, and Al-Bayhaqi in his Sunan)
Third:
Face the Qiblah (the direction of prayer) at the time of slaughtering, as the Qiblah is the most honorable of directions.
Fourth:
Pronounce the name of Allah (Tasmiyah) at the moment of slaughter by saying: "Bismillah ar-Rahman ar-Rahim" (In the Name of Allah, the Most Gracious, the Most Merciful). Even if one forgets to say it, the meat remains lawful (Halal) to eat. Allah, Blessed and Exalted is He, says:
"So eat of that [meat] upon which the name of Allah has been mentioned." (Al-An'am: 118)
It is also recommended to send blessings upon our Master, the Messenger of Allah (peace and blessings be upon him), and to follow it with the Takbeer (Allahu Akbar).
Fifth:
Supplicate for acceptance by saying: "Allahumma hadhihi minka wa ilayka, fa-taqabbal minni" (O Allah, this is a blessing from You and is offered back to You, so please accept it from me). This means: This sacrifice is a blessing that originated from You, and I am offering it to draw closer to You. And Allah the Almighty Knows Best.
How does a praying person prostrate?
All perfect praise be to Allah,The Lord of The Worlds It is from Sunnah that he/she sits with both knees on the ground in order to prostrate, then hands, nose and forehead are placed on the same place. In addition, the toes have to touch the ground, and be directed towards the Qiblah (direction of Ka`bah) during prostration. And Allah Knows Best.
How should the udhiyah be distributed?
Praise be to Allah, and peace and blessings be upon our master, the Messenger of Allah.
It is obligatory to give the poor a portion of the meat from a voluntary sacrifice (Udhiyah al-Tatawwu’), which should not be less than approximately half a kilogram of raw meat. Other parts do not suffice for this obligation, such as the liver, tripe, or intestines.
It is Sunnah for the one offering the sacrifice to divide it into thirds: one-third for himself and his household to eat, one-third to be given as charity to the poor, and one-third to be given as a gift to friends and neighbors, even if they are wealthy. And Allah the Almighty knows best.