ʿUyūn akhbār al-Riḍā

Hadith 146
ahl-al-bayt
146- وَبِهذَا الإِسنادِ عَنْ جَعْفَرِ بْنِ مُحَمَّدٍّ عَلَيْهِمَا السَّلاَمُ قالَ: السَّبتُ لَنا، وَالأَحَدُ لِشِيعَتِنا، وَالإِثنَينِ لِبَني أُمَيَّةَ وَالثُّلاثاءُ لَشيعَتِهِم، وَالأَرْبَعاءُ لِبَني العَبَّاسِ وَالْخَمِيسُ لِشيعَتِهِم وَالجُمُعَةُ لِسائِرٍ النَّاسِ جَمِيعاً، وَلَيْسَ فِيهِ سَفَرٌ، قالَ اللَّهُ تَعالى‏: (فَإِذا قُضِيَتِ الصَّلاةُ فَانْتَشِرُوا فِي الأَرْضِ وَابْتَغُوا مِنْ فَضْلِ اللَّهِ) يَعْنِي يَوْمَ السَّبتِ.
31-146 According to the same documentation, Ja'far ibn Muhammad (al-Sadiq) (as) said: "Saturday is for us, Sunday is for our Shia, Monday is for the Banu Umayya, Tuesday is for their Shia, Wednesday is for the Banu Abbas, Thursday is for their Shia, and Friday is for all people, and there is no travel on that day. Allah, the Most High, has said: 'So when the prayer is finished, then spread through the land and seek the bounty of Allah,' referring to Saturday."
Source: Shaykh Muḥammad b. ʿAlī al-Ṣaduq