Sahih al-Bukhari
Sahih al-Bukhari 154
While passing urine one should not hold his penis with his right hand.
Arabic hadith text
حَدَّثَنَا مُحَمَّدُ بْنُ يُوسُفَ، قَالَ حَدَّثَنَا الأَوْزَاعِيُّ، عَنْ يَحْيَى بْنِ أَبِي كَثِيرٍ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي قَتَادَةَ، عَنْ أَبِيهِ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ "إِذَا بَالَ أَحَدُكُمْ فَلاَ يَأْخُذَنَّ ذَكَرَهُ بِيَمِينِهِ، وَلاَ يَسْتَنْجِي بِيَمِينِهِ، وَلاَ يَتَنَفَّسْ فِي الإِنَاءِ "
Translation
Narrated Abu Qatada
The Prophet (ﷺ) said, "Whenever anyone of you makes water he should not hold his penis or clean his private parts with his right hand. (And while drinking) one should not breathe in the drinking utensil ."