Sahih al-Bukhari 5874
Sahih al-Bukhari · Book 77: Dress · To wear the ring on the little finger
Narrated Anas:
حَدَّثَنَا أَبُو مَعْمَرٍ ، حَدَّثَنَا عَبْدُ الْوَارِثِ ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ صُهَيْبٍ ، عَنْ أَنَسٍ ـ رضى الله عنه ـ قَالَ صَنَعَ النَّبِيُّ صلى الله عليه وسلم خَاتَمًا قَالَ " إِنَّا اتَّخَذْنَا خَاتَمًا، وَنَقَشْنَا فِيهِ نَقْشًا، فَلاَ يَنْقُشْ عَلَيْهِ أَحَدٌ ". قَالَ فَإِنِّي لأَرَى بَرِيقَهُ فِي خِنْصَرِهِ .
The Prophet (ﷺ) got a ring made for himself and said, "I have got a ring made (for myself) and engraved a certain engraving on it so none of you should get such an engraving on his ring." I saw the glitter of the ring on his little finger.