The Prophet ﷺ said, "Ghusl (taking a bath) on Friday is compulsory for every Muslim reaching the age of puberty."  

عَنِ النَّبِيِّ ﷺ قَالَ الْغُسْلُ يَوْمَ الْجُمُعَةِ وَاجِبٌ عَلَى كُلِّ مُحْتَلِمٍ  

(the wife of the Prophet) The people used to come from their abodes and from Al-ʿAwali (i.e. outskirts of Medina up to a distance of four miles or more from Medina). They used to pass through dust and used to be drenched with sweat and covered with dust; so sweat used to trickle from them. One of them came to Messenger of Allah ﷺ who was in my house. The Prophet ﷺ said to him, "I wish that you keep yourself clean on this day of yours (i.e. take a bath)."  

عَنْ عَائِشَةَ زَوْجِ النَّبِيِّ ﷺ قَالَتْ كَانَ النَّاسُ يَنْتَابُونَ يَوْمَ الْجُمُعَةِ مِنْ مَنَازِلِهِمْ وَالْعَوَالِي فَيَأْتُونَ فِي الْغُبَارِ يُصِيبُهُمُ الْغُبَارُ وَالْعَرَقُ فَيَخْرُجُ مِنْهُمُ الْعَرَقُ فَأَتَى رَسُولَ اللَّهِ ﷺ إِنْسَانٌ مِنْهُمْ وَهْوَ عِنْدِي فَقَالَ النَّبِيُّ ﷺ لَوْ أَنَّكُمْ تَطَهَّرْتُمْ لِيَوْمِكُمْ هَذَا  

I asked ʿAmra about taking a bath on Fridays. She replied, " Aisha said, 'The people used to work (for their livelihood) and whenever they went for the Jumua prayer, they used to go to the mosque in the same shape as they had been in work. So they were asked to take a bath on Friday.' "  

كَانَ النَّاسُ مَهَنَةَ أَنْفُسِهِمْ وَكَانُوا إِذَا رَاحُوا إِلَى الْجُمُعَةِ رَاحُوا فِي هَيْئَتِهِمْ فَقِيلَ لَهُمْ لَوِ اغْتَسَلْتُمْ