The Book of Purification
2/18. Chapter:
The prohibition of cleaning oneself with the right hand
Sahih Muslim
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا وَكِيعٌ، عَنْ هِشَامٍ الدَّسْتَوَائِيِّ، عَنْ يَحْيَى بْنِ أَبِي كَثِيرٍ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي قَتَادَةَ، عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِذَا دَخَلَ أَحَدُكُمُ الْخَلاَءَ فَلاَ يَمَسَّ ذَكَرَهُ بِيَمِينِهِ " .
Abu Qatada reported it from his father that the Messenger of Allah (ﷺ) said: When anyone amongst you enters the privy he should not touch his penis with his right hand.
Reference : Sahih Muslim 267bIn-book reference : Book 2, Hadith 81USC-MSA web (English) reference : Book 2, Hadith 512