Sahih Muslim , Book 24, Hadith 5213 (USC-MSA) ⓘ

Ibn Umar reported that Allah's Apostle had made for himself a gold ring; then he discarded it, and then made for himself a silver ring, and had these words engraved upon it (Muhammad, Messenger of Allah), and said: 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.

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَعَمْرٌو النَّاقِدُ، وَمُحَمَّدُ بْنُ عَبَّادٍ، وَابْنُ أَبِي عُمَرَ، - وَاللَّفْظُ لأَبِي بَكْرٍ - قَالُوا حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنْ أَيُّوبَ بْنِ مُوسَى، عَنْ نَافِعٍ، عَنِ ابْنِ، عُمَرَ قَالَ اتَّخَذَ النَّبِيُّ صلى الله عليه وسلم 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 ‏.‏