Muwatta Malik 102
موطأ مالك#102SahihYahya related to me from Malik from Ibn Shihab from Said ibn al- Musayyab that Umar ibn al-Khattab and Uthman ibn Affan and A'isha, the wife of the Prophet, may Allah bless him and grant him peace, used to say, "When the circumcised part touches the circumcised part, ghusl is obligatory
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Salim al-HilaliMauquf Sahih
In-book reference: 2:71