What is the permissible distance between rows in congregational prayer inside a mosque?

Congregational prayer holds great merit as reported in numerous hadiths. ‘Abdullah ibn ‘Umar (may Allah be pleased with them both) narrated that the Messenger of Allah (peace and blessings be upon him and his family) said,
“The congregational prayer is superior to the prayer performed individually by twenty-seven degrees” (recorded by Bukhari).

Praying in the front rows is better than praying in the back rows; al-Bara` ibn ‘Azib (may Allah be pleased with him) narrated that the Messenger of Allah (peace and blessings be upon him and his family) said,
“Indeed, Allah and His angels send blessings upon those praying in the first rows” (recorded by Ahmad in his Musnad, and by Abu Dawud, al-Nisa`i, and Ibn Majah in their respective Sunan). Based on the hadith,
the best rows are those closest to the imam.

 

Row spacing in congregational prayer in a mosque

Jurists are unanimous on the permissibility of spacing between rows, and on the validity of the congregants following the imam in prayer inside a mosque even if there is a considerable distance between them, provided they can know when the imam is performing the motions of prayer. The Hanafi scholar al-Tahṭawi stated in his commentary on Maraqi al-Falah Sharh Nur al-Idah (p. 293), “The expansiveness of the mosque does not prevent [the congregants from following the imam], even if the distance between the rows is considerable. This is because the mosque is considered a single space. Therefore, it is permissible for someone at the far end of a mosque to follow the imam praying in the mihrab.”

The Maliki judge Abu Mohammed ‘Abd al-Wahab ibn ‘Ali ibn Nasr al-Baghdadi noted in Al-Ishraf ‘ala Nukat Masa`il al-Khilaf (1:301), “If a river or nearby road separates the congregants from the imam, and it does not prevent them from seeing the rows or hearing the takbir, it is permissible and does not invalidate their following of the imam.”
Maliki scholars have stipulated that the congregants must know when the imam is performing the motions of prayer, which is achieved by observing the rows and hearing the takbir. If the prayer is valid outside a mosque because the congregants know the imam’s prayer motions by observing the rows and hearing the takbir, then its validity inside a mosque is even greater.

Meanwhile, the Shafi‘i scholar Shams al-Din al-Khatib al-Shirbini mentioned in Mughni al-Muhtaj (1:495),
“If they [the congregants and imam] are both within the same mosque, it is valid to follow [the imam] even if there is a considerable distance between them,” while the Hanbali scholar al-Buhuti noted in Kashshaf al-Qina‘(1:599), “If a congregant can see the imam or those behind him, and both are in the mosque, the prayer of the congregant is valid even if the rows are not connected.”

And Allah Almighty knows best.