Is it valid to perform the obligatory prayer while sitting?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
Standing (Al-Qiyam) while having the ability to do so is one of the pillars (Arkan) of the prayer; the obligatory (Faridah) prayer is not valid without it. However, whoever is unable to stand may pray sitting down. As for voluntary (Nafilah) prayers, it is permissible to pray them sitting even if one is able to stand, but the one sitting receives half the reward of the one who prays standing. And Allah the Exalted knows best.
If someone regularly fasts the six days of Shawwal, are they obligated to fast them every year?
A person is not obligated to fast the six days of Shawwal every year, even if they have made it a habit. However, someone who regularly performs a good deed should not abandon it as long as they are able.
What is the ruling on reciting the Chapter after Al-Faatihah , and what should a worshiper who forgets it do?
All perfect praise be to Allah, The Lord of The Worlds. Any other part of Qur'an that a worshiper reads after Al-Faatihah during the first and the second Rak`ahs is a Sunnah, and forgetting to do so doesn`t nullify prayer, and doesn`t require performing Sujood As-Sahw (prostration of forgetfulness). And Allah Knows Best.
What is the ruling on eating from one`s Udhiyah?
Praise be to Allah, and peace and blessings be upon our master, the Messenger of Allah.
Sacrifices (Udhiyah) are categorized into two types: the Vowed Sacrifice (Al-Mandhurah) and the Voluntary Sacrifice (Al-Tatawwu').
1. The Vowed Sacrifice (Al-Mandhurah)
The vowed sacrifice is obligatory due to the person’s specific oath. It is not permissible for the person offering the sacrifice, nor for those they are legally responsible for financially supporting (dependents), to consume any part of its meat or fat. Furthermore, it is not permissible to benefit from its hide, hair, or any other part.
If they do consume any part of it, they are required to give in charity an equivalent amount of meat or its market value [Tuhfat al-Muhtaj, by Ibn Hajar al-Haytami (9/364)].
2. The Voluntary Sacrifice (Al-Tatawwu’)
Regarding the voluntary sacrifice, it is permissible for the one offering it to eat from its meat, distribute it as gifts to the wealthy, and give it as charity to the poor.
The Obligatory Portion: It is mandatory to give at least a small portion of it in charity to the poor; this portion should not be less than approximately half a kilogram of raw meat. And Allah the Almighty knows best.