Yahya related to me from Malik from Nafi that Abdullah ibn Umar used to say, "When the circumcised part passes the circumcised part, ghusl is obligatory."
Muwatta Malik Book 2, Hadith 76
← Previous Hadith Yahya related to me from Malik from Yahya ibn Said from Abdullah ibn Kab, the mawla of Uthman ibn Affan that Mahmud ibn Labid al-Ansari asked Zayd ibn Thabit about a man who penetrated his wife but became listless and did not ejaculate. Zayd ibn Thabit said, "He does ghusl." Mahmud said to him, "Ubayy ibn Kab used not to think that ghusl was necessary," but Zayd ibn Thabit said, "Ubayy ibn Kab drew away from that before he died."

Muwatta Malik Book 2, Hadith 75 Next Hadith → Yahya related to me from Malik from Abdullah ibn Dinar that Abdullah ibn Umar related that Umar ibn al-Khattab mentioned to the Messenger of Allah, may Allah bless him and grant him peace, that he would sometimes become junub in the night. The Messenger of Allah, may Allah bless him and grant him peace, said to him, "Do wudu and wash your penis, and then sleep."

Muwatta Malik Book 2, Hadith 77