Yahya related to me from Malik from Abu'n-Nadr, the mawla of Umaribn Ubaydullah from Ibn Aflah, the mawla of Abu Ayyub al-Ansari froman umm walad of Abu Ayyubal-Ansari that he practised coitusinterruptus.
USC-MSA web (English) reference: Book 29, Hadith 97
Arabic reference: Book 29, Hadith 1262