Sahih al-Bukhari
Sahih al-Bukhari 858
The ablution for boys (youngsters). When they should perform Ghusl (take a bath) and Tuhur (purification). Their attendance at congregational prayers and their rows in the prayers.
Arabic hadith text
حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللَّهِ، قَالَ حَدَّثَنَا سُفْيَانُ، قَالَ حَدَّثَنِي صَفْوَانُ بْنُ سُلَيْمٍ، عَنْ عَطَاءِ بْنِ يَسَارٍ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ "الْغُسْلُ يَوْمَ الْجُمُعَةِ وَاجِبٌ عَلَى كُلِّ مُحْتَلِمٍ "
Translation
Narrated Abu Sa`id Al-Khudri
The Prophet (ﷺ) said, "Ghusl (taking a bath) on Friday is compulsory for every Muslim reaching the age of puberty."