Muwatta Malik 93
Purity
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ، أَنَّهُ قَالَ رَأَيْتُ أَبِي عَبْدَ اللَّهِ بْنَ عُمَرَ يَغْتَسِلُ ثُمَّ يَتَوَضَّأُ فَقُلْتُ لَهُ يَا أَبَتِ أَمَا يَجْزِيكَ الْغُسْلُ مِنَ الْوُضُوءِ قَالَ بَلَى وَلَكِنِّي أَحْيَانًا أَمَسُّ ذَكَرِي فَأَتَوَضَّأُ .
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
Grading: Salim al-Hilali: Mauquf Sahih
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.