وَقَالَ اَلصَّادِقُ عَلَيْهِ اَلسَّلاَمُ: فِي عِلَّةِ غُسْلِ يَوْمِ اَلْجُمُعَةِ «إِنَّ اَلْأَنْصَارَ كَانَتْ تَعْمَلُ فِي نَوَاضِحِهَا وَ أَمْوَالِهَا فَإِذَا كَانَ يَوْمُ اَلْجُمُعَةِ حَضَرُوا اَلْمَسْجِدَ فَتَأَذَّى اَلنَّاسُ بِأَرْوَاحِ آبَاطِهِمْ وَ أَجْسَادِهِمْ فَأَمَرَهُمْ رَسُولُ اَللَّهِ صَلَّى اَللَّهُ عَلَيْهِ وَ آلِهِ بِالْغُسْلِ فَجَرَتْ بِذَلِكَ اَلسُّنَّةُ.
Imam Jafar ibn Muhammad Al-Sadiq (a.s) said regarding the reason for the Jumu’ah (ritual bath): 'The Ansar (residents of Medina who supported the Prophet) used to work in their fields and with their livestock. When Jumu’ah came, they would attend the mosque, and the people were bothered by the odor from their armpits and bodies. So the Messenger of Allah (saws) ordered them to perform ghusl, and thus it became a Sunnah (established practice).'