What is the ruling on making up missed fasts from many years?
A Muslim must make up for any missed fasts, as they are a debt owed to Allah. The Prophet ﷺ said:
"The debt owed to Allah is more deserving of being fulfilled." [Narrated by Muslim]
Whoever has missed fasts must make them up as long as they are alive and capable of fasting.
What should a person, who doubts the validity of his Wudu, or over performs it, do?
One who doubts the validity of his/her Wudu while performing it should redo it until he/she is certain of having attained purity. But, if doubt was after having performed Wudu, then he/she should not pay attention to that as doubt after the end of an act of worship does not count. This is of course in case doubt was within the reasonable limits since once it goes beyond that, it becomes a whispering of the Shaytaan (devil) which he/she should ignore as the Wudu is valid.
What is the ruling on performing the Witr prayer as a single rak`ah?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
It is permissible to perform the Witr prayer as a single unit (rak‘ah). It was narrated from Ibn ‘Umar that a man asked the Messenger of Allah ﷺ about the night prayer, and the Messenger of Allah ﷺ replied: 'The night prayer is offered two by two (mathna mathna). If one of you fears the approach of dawn, let him pray a single rak‘ah to make what he has prayed odd-numbered (Witr) for him.' (Related by al-Bukhari & Muslim)). However, limiting the prayer to only one rak‘ah is considered 'contrary to the preferred way' (Khilaf al-Awla).
It is stated in Al-Minhaj al-Qawim Sharh al-Muqaddimah al-Hadramiyyah (p. 137): 'The minimum of Witr is one rak‘ah, but limiting it to that is contrary to what is best.'
The most complete form of Witr is eleven units, while the minimum level of 'perfection' is three units. It is stated in ‘Umdat al-Salik (p. 60): 'The minimum of Witr is one rak‘ah, and its maximum is eleven, performing the taslim (salutation) after every two units. The lowest level of perfection is three units with two separate taslims (meaning 2+1).' And Allah the Exalted knows best.
What is the ruling on praying seated due to severe obesity, given that I experience hardship in performing the prayer — especially when rising from the ground after sujūd to perform the next rak‘ah?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
Standing, when one is able to do so, is a pillar of the prayer. However, whoever would experience severe, intolerable hardship, or fears harm to himself or to a limb due to obesity, or finds that standing causes him to lose his khushū‘ (humble focus and concentration) in prayer, then there is no objection to his praying seated on a chair or on the ground, performing rukū‘ (bowing) and sujūd (prostration) through gesture — provided that the gesture for sujūd is made lower than that for rukū‘. Whoever is able, at any point, to properly perform any one of these pillars, is obligated to perform it in full; for omitting it is a concession that applies only in cases of genuine inability. The Prophet ﷺ said: "When I command you to do something, do of it whatever you are able." (Related by al-Bukhārī). As the scholars of fiqh have established: what remains possible is not waived on account of what is difficult.
The criterion for determining genuine inability, as chosen by Imam al-Ḥaramayn al-Juwaynī (raḥimahullāh), is that the worshipper experiences hardship that causes him to lose his khushū‘.
As for voluntary (nafl) prayer, there is no objection to performing it while seated, even if one is able to stand. However, rukū‘ and sujūd must still be performed [in their proper physical form] by anyone who is able to do so. And Allah, the Exalted, knows best.
