"I see that your companion (the Prophet) is teaching you everything, even how to relieve yourselves?" He said: "Yes indeed. He has ordered us not to face the Qiblah (prayer direction) nor to clean ourselves with our right hands, and not to be content with anything less than three stones, which are not to include any excrement or bones." (Using translation from Ibn Mājah 316)
بَعْضُ الْمُشْرِكِينَ وَهُمْ يَسْتَهْزِئُونَ بِهِ إِنِّي لَأَرَى صَاحِبَكُمْ يُعَلِّمُكُمْ حَتَّى الْخِرَاءَةِ قَالَ سَلْمَانُ أَجَلْ أَمَرَنَا أَنْ لَا نَسْتَقْبِلَ الْقِبْلَةَ وَلَا نَسْتَنْجِيَ بِأَيْمَانِنَا وَلَا نَكْتَفِيَ بِدُونِ ثَلَاثَةِ أَحْجَارٍ لَيْسَ فِيهَا رَجِيعٌ وَلَا عَظْمٌ