Al-Kāfi - The Book of Prayer

7.Muhammad ibn Yahya has narrated from Muhammad ibn Musa from al-‘ Abbas ibn The Ma’ruf from ibn abu Najran from ‘Abd Allah ibn Sinan from ibn abu Ya‘fur from abu Hamzah who has said the following: “Abu Ja’far (a.s.), has said, in answer to a question, ’How was Friday called Friday?’ The Imam said, ’Allah, the Most Majestic, the Most Glorious, brought His creatures under the Divine Authority of Muhammad (a.s.), and the Executor of his will during “the divine Covenant session”, and that session was called “al-Jumu‘ah” (the assembly) because of His calling His creatures together.’” جهول - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (5/342))