كتاب 2
2  
Book 2
(2)
Chapter 2
(2)
باب 2
Muwatta Malik 93
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."
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، أَنَّهُ كَانَ يَقُولُ مَنْ مَسَّ ذَكَرَهُ فَقَدْ وَجَبَ عَلَيْهِ الْوُضُوءُ ‏.‏
Reference : Muwatta Malik 93
In-book reference : Book 2, Hadith 34271
USC-MSA web (English) reference : Book 7, Hadith 93
  (deprecated numbering scheme)