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 it permissible to offer an Udhiyah on behalf of the deceased?
In the Name of Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
Offering an Udhiyah (sacrificial animal) on behalf of a deceased person is permissible. This is the official position of the Hanbali school (as stated in Kashshaf al-Qina’ by al-Bahuti,Vol.6/P.428) and was also upheld by the prominent Shafi'i scholar Al-’Abbadi (mentioned in Bidayat al-Muhtaj by Ibn Qadi Shuhbah,Vol. 4/P.358). It has likewise been narrated as a valid view among some Maliki and Hanafi scholars.
In fact, Imam Abu Dawud dedicated an entire chapter in his Sunan collection entitled, "Chapter on Sacrificing on Behalf of the Deceased." In it, he recorded a narration from Hanash, who said: "I saw 'Ali sacrificing two rams, so I asked him, 'What is this?' He replied, 'The Messenger of Allah (peace and blessings be upon him) commanded me to offer a sacrifice on his behalf, so I am sacrificing on his behalf.'"
Imam Abu Dawud also narrated from Jabir (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "O Allah, this is from You, for You, and on behalf of Muhammad and his Ummah (community). In the Name of Allah, and Allah is the Greatest," and he then slaughtered the animal.
The textual evidence here lies in the fact that our Master, the Prophet (peace and blessings be upon him), offered a sacrifice on behalf of his entire community—and it is well-established that his community includes those who have already passed away.
Furthermore, there is an abundance of sacred texts demonstrating that the rewards of righteous deeds reach the deceased. For instance, it is permissible to fast on behalf of a deceased person who passed away with missed obligatory fasts, and it is equally permissible to perform Hajj on their behalf, both of which are firmly established in authentic Hadiths. Therefore, if the reward of fasting (which is a purely physical act of worship) and Hajj (which is a joint physical and financial act of worship) can reach the deceased, then the reward of an Udhiyah reaches them with greater reason (by way of A Fortiori argument). This is because it is a purely financial act of worship, falling under the general category of charity (Sadaqah).
Additionally, scholars have reached a consensus (Ijma') that the rewards of charity reach the deceased, and since the Udhiyah is inherently an act of charity, it falls under the same ruling. Consequently, based on all the aforementioned evidence, we hold the view that offering a sacrifice on behalf of the deceased is entirely permissible. And Allah the Almighty Knows Best.
Is it permissible for women to attend Tarawih prayer in the mosque?
Yes, it is permissible for women to attend Tarawih prayer in the mosque, provided they observe modesty, proper covering, and avoid mixing with men.
The Prophet ﷺ said: "Do not prevent the female servants of Allah from the mosques of Allah." [Bukhari and Muslim]
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.