What is the ruling on combining prayers in prison without shortening them for a group ranging from 13 to 20 people, given the presence of only one restroom which takes a long time for ablution, ritual bathing, and answering the call of nature? And what is the ruling on someone who does so believing it to be permissible, based on the Prophet's hadith (peace be upon him) that he combined prayers neither due to travel nor rain?

If prisoners are unjustly detained in a country that is a qasr distance (distance permitting shortening of prayers) away from their home country, they are permitted to avail themselves of travel concessions, such as combining prayers. As for those who are not in such a situation, some scholars permit combining prayers for any general need, to alleviate hardship, based on the action of the Prophet, peace be upon him. There is no blame on whoever adopts this opinion. It is preferable for prisoners to observe the prayer times as much as possible, or to perform a "formal" combination by praying the first prayer at the very end of its prescribed time and the second prayer at the very beginning of its prescribed time.