No one should engrave anything like the engraving of this signet ring of mine. And when he wore it, he kept its stone towards the inside of his palm, and it was this which fell down (from the hands) of Mu'ayqib into the well of Aris.  

اتَّخَذَ النَّبِيُّ ﷺ خَاتَمًا مِنْ ذَهَبٍ ثُمَّ أَلْقَاهُ ثُمَّ اتَّخَذَ خَاتَمًا مِنْ وَرِقٍ وَنَقَشَ فِيهِ مُحَمَّدٌ رَسُولُ اللَّهِ وَقَالَ لاَ يَنْقُشْ أَحَدٌ عَلَى نَقْشِ خَاتَمِي هَذَا وَكَانَ إِذَا لَبِسَهُ جَعَلَ فَصَّهُ مِمَّا يَلِي بَطْنَ كَفِّهِ وَهُوَ الَّذِي سَقَطَ مِنْ مُعَيْقِيبٍ فِي بِئْرِ أَرِيسٍ  

"The Prophet [SAW] wore a ring of gold, then he discarded it and wore a ring of silver on which were engraved (the words) 'Muhammad Rasul Allah.' Then he said: 'No one should copy this inscription of mine.' And he wore the stone (Fass) toward his palm."  

كَانَ النَّبِيُّ ﷺ يَتَخَتَّمُ بِخَاتَمٍ مِنْ ذَهَبٍ ثُمَّ طَرَحَهُ وَلَبِسَ خَاتَمًا مِنْ وَرِقٍ وَنُقِشَ عَلَيْهِ مُحَمَّدٌ رَسُولُ اللَّهِ ثُمَّ قَالَ لاَ يَنْبَغِي لأَحَدٍ أَنْ يَنْقُشَ عَلَى نَقْشِ خَاتَمِي هَذَا وَجَعَلَ فَصَّهُ فِي بَطْنِ كَفِّهِ  

"The Prophet [SAW] used to wear a ring of gold, then he discarded it, and put on a ring of silver on which was engraved (the words): 'Muhammad Rasul Allah.' He said: 'No one else should engrave his ring with an inscription like this ring of mine.' Then he put the stone toward the palm of his hand." (Using translation from Nasāʾī 5216)  

كَانَ النَّبِيُّ ﷺ تَخَتَّمَ خَاتَمًا مِنْ ذَهَبٍ ثُمَّ طَرَحَهُ وَلَبِسَ خَاتَمًا مِنْ وَرِقٍ وَنُقِشَ عَلَيْهِ مُحَمَّدٌ رَسُولُ اللهِ وَقَالَ «لَا يَنْبَغِي لِأَحَدٍ أَنْ يَنْقُشَ عَلَى نَقْشِ خَاتَمِي هَذَا» وَجَعَلَ فَصَّهُ فِي بَطْنِ كَفِّهِ