On Fridays the Dhuhr prayer is displaced for those who attend the mosque by the Jumu'ah, the congregational Friday prayer, which the Qur'an commands the community to hasten toward when the call is given. Jumu'ah is two rak'ah rather than four, prayed aloud, and preceded by a sermon in two parts; attendance is an obligation on adult men in most Sunni reckonings, with women, travellers and the sick excused though not excluded. Where it cannot be held, the ordinary four-rak'ah Dhuhr is prayed in its place.
Dhuhr is also the prayer around which the permitted combining of prayers is discussed. Twelver Shia practice regularly joins Dhuhr and the following Asr into a single sitting, and Sunni law allows the two to be combined for travellers and in hardship, so that the midday and afternoon obligations, though distinct, are the pair most often prayed together.
Classical jurists disputed the minimum congregation Jumu'ah requires to be valid: the Shafii school historically required forty free adult male residents present, a threshold that could leave small or traveling communities unable to hold the prayer at all, while the Hanafi school set a far lower bar, requiring only the ruler's permission and a small quorum beyond the imam, a difference that shaped how readily the rite could be established in newly settled or minority communities. The obligation itself is grounded in the Quran's own naming of the day, Surah al-Jumu'ah (62:9-11), which commands believers to hasten to the remembrance of God and leave off trade when the call is sounded, a text read as making Friday, rather than the Jewish Saturday or Christian Sunday, the distinctive day of congregational assembly in Islam.