Sunan an-Nasa'i, Book 14, Hadith 1388 (In-Book) ⓘ
It was narrated from Abu Sa'eed Al-Khudri that: The Messenger of Allah said: "Ghusl on Friday is obligatory for everyone who has reached the age of puberty."
أَخْبَرَنَا قُتَيْبَةُ، عَنْ مَالِكٍ، عَنْ صَفْوَانَ بْنِ سُلَيْمٍ، عَنْ عَطَاءِ بْنِ يَسَارٍ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " غُسْلُ يَوْمِ الْجُمُعَةِ وَاجِبٌ عَلَى كُلِّ مُحْتَلِمٍ " .
also referenced under: Volume 2, Book 14, Hadith 1378 (DarusSalam)