Book 2, Number 2.16.60: Yahya related to me from Malik that Abdullah ibn Abi Bakr ibn Muhammad ibn Amr ibn Hazim heard Urwa ibn az−Zubayr saying, "I went to see Marwan ibn al−Hakam and we talked about what you had to do wudu for, and Marwan said, 'You have to do wudu if you touch your penis.' Urwa said, 'I didn't know that.' Marwan ibn al−Hakam said that Busra bint Safwan had told him that she heard the Messenger of Allah, may Allah bless him and grant him peace, say, 'If any of you touches his penis he should do wudu.' "
Book 2, Number 2.16.61: Yahya related to me from Malik from Ismail ibn Muhammad ibn Sad ibn Abi Waqqas that Musab ibn Sad ibn Abi Waqqas said, "I was holding the Book for Sad ibn Abi Waqqas and I rubbed myself. Sad said, 'Did you touch your penis?' I replied, 'Yes,' and he said, 'Get up and do wudu.' So I got up and did wudu and then returned."
Book 2, Number 2.16.62: Yahya related to me from Malik from Nafi that Abdullah ibn Umar used to say, "If you touch your penis you have to do wudu."
Book 2, Number 2.16.63: Yahya related to me from Malik from Hisham ibn Urwa that his father used to say, "If any of you touches his penis he has to do wudu."
Book 2, Number 2.16.64: Yahya related from Malik from Ibn Shihab that Salim ibn Abdullah said, "I saw my father Abdullah ibn Umar, do ghusl and then do wudu. I said to him, 'Father, isn't ghusl enough for you?' He said, 'Of course, but sometimes I touch my penis, so I do wudu.' "
Book 2, Number 2.16.65: Yahya related to me from Malik from Nafi that Salim ibn 'Abdullah said, "I was with Abdullah ibn Umar on a journey and after the sun had risen I saw him do wudu and then pray. So I said to him, 'This isn't a prayer that you normally do. 'He said, 'After I had done wudu for the subh prayer, I touched my genitals. Then I forgot to do wudu. So I did wudu again and repeated my prayer.' "
Book 2, Number 2.16.61: Yahya related to me from Malik from Ismail ibn Muhammad ibn Sad ibn Abi Waqqas that Musab ibn Sad ibn Abi Waqqas said, "I was holding the Book for Sad ibn Abi Waqqas and I rubbed myself. Sad said, 'Did you touch your penis?' I replied, 'Yes,' and he said, 'Get up and do wudu.' So I got up and did wudu and then returned."
Book 2, Number 2.16.62: Yahya related to me from Malik from Nafi that Abdullah ibn Umar used to say, "If you touch your penis you have to do wudu."
Book 2, Number 2.16.63: Yahya related to me from Malik from Hisham ibn Urwa that his father used to say, "If any of you touches his penis he has to do wudu."
Book 2, Number 2.16.64: Yahya related from Malik from Ibn Shihab that Salim ibn Abdullah said, "I saw my father Abdullah ibn Umar, do ghusl and then do wudu. I said to him, 'Father, isn't ghusl enough for you?' He said, 'Of course, but sometimes I touch my penis, so I do wudu.' "
Book 2, Number 2.16.65: Yahya related to me from Malik from Nafi that Salim ibn 'Abdullah said, "I was with Abdullah ibn Umar on a journey and after the sun had risen I saw him do wudu and then pray. So I said to him, 'This isn't a prayer that you normally do. 'He said, 'After I had done wudu for the subh prayer, I touched my genitals. Then I forgot to do wudu. So I did wudu again and repeated my prayer.' "