It was narrated that Anas bin Malik said:"The Messenger of Allah [SAW] put on a ring, and he had some words inscribed on it. He said: 'We have put on a ring and have had some words engraved on it; no one of you should copy this inscription.'" Then Anas said: "It is as if I can see its whiteness on his hand."
أَخْبَرَنَا أَبُو دَاوُدَ، سُلَيْمَانُ بْنُ سَيْفٍ الْحَرَّانِيُّ قَالَ حَدَّثَنَا هَارُونُ بْنُ إِسْمَاعِيلَ، قَالَ حَدَّثَنَا عَلِيُّ بْنُ الْمُبَارَكِ، قَالَ حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ صُهَيْبٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ اتَّخَذَ رَسُولُ اللَّهِ صلى الله عليه وسلم خَاتَمًا وَنَقَشَ عَلَيْهِ نَقْشًا قَالَ " إِنَّا قَدِ اتَّخَذْنَا خَاتَمًا وَنَقَشْنَا فِيهِ نَقْشًا فَلاَ يَنْقُشْ أَحَدٌ عَلَى نَقْشِهِ " . ثُمَّ قَالَ أَنَسٌ فَكَأَنِّي أَنْظُرُ إِلَى وَبِيصِهِ فِي يَدِهِ .
Nesai
The Book of Adornment • Hadith 5208