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.
He said: Muhammad [bin Isma'il] said: This is the most correct thing related from the Prophet (ﷺ) on this topic.