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