"When any one of you drinks, let him not breathe into the vessel, and when he goes to the toilet let him not touch his penis with his right hand, nor wipe himself with this right hand."  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا شَرِبَ أَحَدُكُمْ فَلاَ يَتَنَفَّسْ فِي إِنَائِهِ وَإِذَا أَتَى الْخَلاَءَ فَلاَ يَمَسَّ ذَكَرَهُ بِيَمِينِهِ وَلاَ يَتَمَسَّحْ بِيَمِينِهِ  

It was narrated from Ibn Abi Qatadah, from his father, that the Prophet ﷺ forbade breathing into the vessel (when drinking), touching one's penis with one's right hand, and cleaning oneself with one's right hand.  

أَنَّ النَّبِيَّ ﷺ نَهَى أَنْ يَتَنَفَّسَ فِي الإِنَاءِ وَأَنْ يَمَسَّ ذَكَرَهُ بِيَمِينِهِ وَأَنْ يَسْتَطِيبَ بِيَمِينِهِ  

"The idolators said: 'We see that your companion teaches you how to go to the toilet.' He said: 'Yes, he forbade us from cleaning ourselves with our right hand, and from facing toward the Qiblah, and he said: 'None of you should clean with less than three stones.'"  

الْمُشْرِكُونَ إِنَّا لَنَرَى صَاحِبَكُمْ يُعَلِّمُكُمُ الْخِرَاءَةَ قَالَ أَجَلْ نَهَانَا أَنْ يَسْتَنْجِيَ أَحَدُنَا بِيَمِينِهِ وَيَسْتَقْبِلَ الْقِبْلَةَ وَقَالَ لاَ يَسْتَنْجِي أَحَدُكُمْ بِدُونِ ثَلاَثَةِ أَحْجَارٍ