When does a traveler begin to shorten prayers (qasr), is it after passing the last buildings or after covering a distance of 80 kilometers? And what should one do if the buildings are contiguous between their area and the neighboring area? And if one enters the mosque to pray Dhuhr shortened and finds the congregation praying four rak'ahs, and their time is limited, what should they do? And is attending the mosque and congregational prayer obligatory even if one's time is not limited?

The distance for qasr (shortening prayers) agreed upon by the majority of scholars is approximately 83 kilometers (four burud). The travel distance begins from the last inhabited part of the town. Whoever travels this distance, for a permissible purpose, is allowed to avail himself of the concessions of travel, such as qasr. However, he should not begin doing so until he has passed beyond the houses of the city. If a traveler prays behind a resident (non-traveler), he must complete his prayer, and this is the Sunnah. As for a traveler praying individually and shortening his prayer, there is no harm in that. A traveler is not obligated to attend the Friday prayer (Jumu'ah) or congregational prayers (Jama'ah).