The imam recited a verse containing a prostration of recitation (*sajdat al-tilāwah*) but did not prostrate. After the imam's *salām*, a follower (*maʾmūm*) performed a prostration of forgetfulness (*sujūd al-sahw*) because the imam had not performed the prostration of recitation. Is it permissible to go against the imam in this way?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
There is no sin on the imam if he omits the prostration of recitation (sujūd al-tilāwah), even deliberately. The maʾmūm (the one following the imam) is obliged to follow the imam in the prayer, so if the imam does not perform the prostration of recitation, it is not permissible for the follower to prostrate, because the imam is appointed only to be followed.
If the follower introduces a prostration after the imam’s salām but before his own salām, in a case where there is no prostration of forgetfulness (sujūd al-sahw), his prayer is invalidated if he knew it to be prohibited. Otherwise, he is excused on account of his ignorance and his prayer is not invalidated.
It is stated in Ḥāshiyat al-Imām al-Jamal ʿalā Fatḥ al-Wahhāb: “His statement: ‘So the omission of the hayʾāt (the non-essential sunnahs of the prayer) is not compensated for by prostration; if one prostrates for any of them deliberately, his prayer is invalidated, unless he is excused due to his ignorance.’”
Since this issue is one that is hidden from the laymen, as it is among the subtleties of knowledge, and the laymen are excused for ignorance of whatever is of such a nature, and their act of obedience is not invalidated because of it, it may be said that the prayer of one who has not acquired knowledge of this issue is not invalidated, with the necessity of learning the rulings remaining. As for after knowing it, the prayer is invalidated. And Allah Almighty knows best.
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.
Should missed Sunnah prayer be made up?
Making up missed voluntary acts of worship is from Sunnah.
Does sacrificing one sheep avail for the entire household?
In the Name of Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
Offering an Udhiyah (sacrificial offering) is a communal Sunnah (Sunnah Kifayah) for members of the same household, provided that their financial maintenance is undertaken by a single provider. By "communal Sunnah," we mean that when one person performs it, the religious recommendation is fulfilled on behalf of the entire household, though the spiritual reward itself belongs uniquely to the one who offered it.
Therefore, if any member of the household performs the sacrifice—even if it is someone who is not legally responsible for the household's expenses, such as the wife or one of the children—the recommendation is fulfilled for everyone in that home. However, the reward does not automatically extend to the other members unless the person offering the sacrifice explicitly intends to share the reward with them—similar to how performing a funeral prayer (Janazah) fulfills the communal obligation for everyone, yet the specific reward is earned by those who actually prayed.
Additionally, a single sacrifice is sufficient for a man who is married to more than one wife. And Allah the Almighty Knows Best.