Jami` at-Tirmidhi 1744
Narrated Hammad bin Salamah:
"I saw Ibn Rafi' [and he is 'Ubaidullah bin Abi Rafi', the freed slave of the Messenger of Allah (ﷺ) - and Aslam was the name of Ibn Abi Rafi] wearing a ring on his right, so I asked him about that. He said, 'I saw 'Abdullah bin Ja'far wearing a ring on his right hand, and he ['Abdullah bin Ja'far] said: "The Messenger of Allah (ﷺ) wore a ring on his right hand."
حَدَّثَنَا أَحْمَدُ بْنُ مَنِيعٍ، حَدَّثَنَا يَزِيدُ بْنُ هَارُونَ، عَنْ حَمَّادِ بْنِ سَلَمَةَ، قَالَ رَأَيْتُ ابْنَ أَبِي رَافِعٍ يَتَخَتَّمُ فِي يَمِينِهِ فَسَأَلْتُهُ عَنْ ذَلِكَ، فَقَالَ رَأَيْتُ عَبْدَ اللَّهِ بْنَ جَعْفَرٍ يَتَخَتَّمُ فِي يَمِينِهِ ‏.‏ وَقَالَ عَبْدُ اللَّهِ بْنُ جَعْفَرٍ كَانَ النَّبِيُّ صلى الله عليه وسلم يَتَخَتَّمُ فِي يَمِينِهِ ‏.‏ قَالَ وَقَالَ مُحَمَّدُ بْنُ إِسْمَاعِيلَ هَذَا أَصَحُّ شَيْءٍ رُوِيَ فِي هَذَا الْبَابِ ‏.‏