What is the ruling on congratulating others on the arrival of Ramadan?
Congratulating others on the arrival of Ramadan is permissible.
If someone does it to express their love for worship and the blessings of Ramadan, and congratulates their fellow Muslim, they have done something good.
The Prophet ﷺ said: "Shall I not tell you something that, if you do it, you will love one another? Spread peace (Salam) among yourselves." [Narrated by Muslim]
Giving Salam is a prayer for peace and safety.
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.
What should one who doubts the validity of his ablution and performs it frequently do?
Whoever doubts the validity of his ablution after finishing it, his ablution is valid. This is because the default is the validity of the ablution, and because doubt after finishing an act of worship doesn`t affect its validity. And Allah the Almighty knows best.
What is the ruling on the follower (*maʾmūm*) reciting Sūrat al-Fātiḥah behind the imam?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
In our school of Islamic thought, the Shāfiʿī school, reciting al-Fātiḥah is obligatory in every rakʿah of the prayer for the imam, the follower (maʾmūm), and the one praying individually (munfarid), because it is one of the pillars (arkān) of the prayer. Whoever does not perform it, his prayer is invalid, whether the prayer is silent (sirriyyah) or audible (jahriyyah), based on the saying of the Prophet (peace and blessings be upon him): “The prayer of the one who does not recite the Opening of the Book (Fātiḥat al-Kitāb) is invalid.” Agreed upon.
It is stated in ʿUmdat al-Sālik, one of the books of the Shāfiʿī school: “He recites al-Fātiḥah in every rakʿah, whether he is the imam, the follower, or the individual worshipper.”
The jurists of the other schools hold a different opinion, which was previously explained in Fatwa no. (
3169); please refer to it. And Allah Almighty knows best.