He used to wear the ring on his right hand. Abdullah bin Jafar said, "The Prophet ﷺ used to wear the ring on his right hand."Muhammad bin Ismail said, "This is the most authentic narration reported from the Prophet ﷺ on this subject."
حدثنا أحمد بن منيع حدثنا يزيد بن هارون عن حماد بن سلمة قال رأيت ابن أبي رافع يتختم في يمينه فسألته عن ذلك فقال
يتختم في يمينه وقال عبد الله بن جعفر كان النبي ﷺ يتختم في يمينه قال و قال محمد بن إسمعيل هذا أصح شيء روي عن النبي ﷺ في هذا الباب
[Its isnad is sahih]. Nasai narrated it in "Zinah," in the chapter "The place of the ring on the hand... etc.," 8/175, no. 5207, from the hadith of Hammad bin Salama, with the same wording. The hadith has corroborating narrations in Abu Dawud, no. 4226, and elsewhere.