I see that your friend even teaches you about the excrement. He replied; Yes, he has in fact forbidden us that anyone amongst us should cleanse himself with his right hand, or face the Qibla. He has forbidden the use of dung or bone for it, and he has also instructed us not to use less than three pebbles (for this purpose).  

لَنَا الْمُشْرِكُونَ إِنِّي أَرَى صَاحِبَكُمْ يُعَلِّمُكُمْ حَتَّى يُعَلِّمَكُمُ الْخِرَاءَةَ فَقَالَ أَجَلْ إِنَّهُ نَهَانَا أَنْ يَسْتَنْجِيَ أَحَدُنَا بِيَمِينِهِ أَوْ يَسْتَقْبِلَ الْقِبْلَةَ وَنَهَى عَنِ الرَّوْثِ وَالْعِظَامِ وَقَالَ لاَ يَسْتَنْجِي أَحَدُكُمْ بِدُونِ ثَلاَثَةِ أَحْجَارٍ  

"Your companion (meaning, the Prophet ﷺ) even teaches you how to go to the toilet!" He said: "Yes, he forbade us from facing the Qiblah when defecating or urinating, or cleaning ourselves with out right hands, or to use less than three stones."  

لَهُ رَجُلٌ إِنَّ صَاحِبَكُمْ لَيُعَلِّمُكُمْ حَتَّى الْخِرَاءَةَ قَالَ أَجَلْ نَهَانَا أَنْ نَسْتَقْبِلَ الْقِبْلَةَ بِغَائِطٍ أَوْ بَوْلٍ أَوْ نَسْتَنْجِيَ بِأَيْمَانِنَا أَوْ نَكْتَفِيَ بِأَقَلَّ مِنْ ثَلاَثَةِ أَحْجَارٍ  

"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  

I see that your friend even teaches you about the excrement. He replied; Yes, he has in fact forbidden us that anyone amongst us should cleanse himself with his right hand, or face the Qibla. He has forbidden the use of dung or bone for it, and he has also instructed us not to use less than three pebbles (for this purpose). (Using translation from Muslim 262b)  

لَهُ الْمُشْرِكُونَ إِنَّا نَرَى صَاحِبَكُمْ يُعَلِّمُكُمْ حَتَّى يُعَلِّمَكُمُ الْخِرَاءَةَ قَالَ أَجَلْ إِنَّهُ يَنْهَانَاأَنْ يَسْتَنْجِيَ أَحَدُنَا بِيَمِينِهِ أَوْ يَسْتَقْبِلَ الْقِبْلَةَ وَيَنْهَانَا عَنِ الرَّوْثِ وَالْعِظَامِ وَقَالَ لَا يَسْتَنْجِي أَحَدُكُمْ بِدُونِ ثَلَاثَةِ أَحْجَارٍ  

[Machine] I have a man from the polytheists and by Allah, I see your companion teaching you everything until he teaches you defecation. He said: Yes, he forbade us from facing the Qibla (direction of prayer), and from cleansing ourselves with our right hands, and from cleansing ourselves with less than three stones, and from cleansing ourselves with dung or bone.  

لِي رَجُلٌ مِنَ الْمُشْرِكُينَ وَاللهِ إِنِّي لَأَرَى صَاحِبَكُمْ يُعَلِّمُكُمْ كُلَّ شَيْءٍ حَتَّى يُعَلِّمَكُمُ الْخَرْأَةَ قَالَ أَجَلْ «نَهَانَا أَنْ نَسْتَقْبِلَ الْقِبْلَةَ وَأَنْ نَسْتَنْجِيَ بِأَيْمَانِنَا وَأَنْ نَسْتَنْجِيَ بِدُونِ ثَلَاثَةِ أَحْجَارٍ وَأَنْ نَسْتَنْجِيَ بِرَجِيعٍ أَوْ عَظْمٍ»  

"عَنْ سَلْمَانَ: أَنَّهُ قَالَ لَهُ بَعْضُ الْمُشْرِكِينَ وَهُمْ يَسْتَهْزِئُونَ: أَرَى صَاحِبَكُمْ عَلَّمَكُمْ كُلَّ شَىْءٍ حَتَّى الخِرَاءَةَ (*)، فَقَالَ سَلْمَانُ: أَجَلْ أَمَرَنَا أَنْ لَا نَسْتقْبِلَ القِبْلَةَ بِغَائِطٍ، وَلَا بَوْلٍ، وَلَا نَسْتَنْجِى بأَيْمَانِنَا، وَلَا نَكْتَفِى بِدُونِ ثَلَاثَةِ أَحْجَارٍ لَيْسَ فِيهَا رَجِيعٌ (* *)، وَلَا عَظْمٌ".