Al-Kāfi - Volume 3 > Necessity of Ghusl (bath) on Friday
Hadith #1

1ـ عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنْ عَبْدِ الله بْنِ الْمُغِيرَةِ عَنْ أَبِي الْحَسَنِ الرِّضَا (عَلَيْهِ الْسَّلام) قَالَ سَأَلْتُهُ عَنِ الْغُسْلِ يَوْمَ الْجُمُعَةِ فَقَالَ وَاجِبٌ عَلَى كُلِّ ذَكَرٍ وَأُنْثَى عَبْدٍ أَوْ حُرٍّ.

1. Ali ibn Ibrahim has narrated from his father from ’Abd Allah ibn al-Mughirah who has said the following: “I once asked abu al-Hassan, al-Rida, ‘Alayhi al-Salam, about Ghusl (bath) on Friday. He (the Imam) said, ‘It is obligatory on every male, female, slave or free.’”