Sunan an-Nasa'i, Volume 6, Book 48, Hadith 5289 (DarusSalam) ⓘ
It was narrated that 'Ali said: "The Messenger of Allah [SAW] forbade me to wear (a ring) on this finger," and it was on the middle finger and the one next to it.
أَخْبَرَنَا هَنَّادُ بْنُ السَّرِيِّ، عَنْ أَبِي الأَحْوَصِ، عَنْ عَاصِمِ بْنِ كُلَيْبٍ، عَنْ أَبِي بُرْدَةَ، عَنْ عَلِيٍّ، قَالَ نَهَانِي رَسُولُ اللَّهِ صلى الله عليه وسلم أَنْ أَلْبَسَ فِي إِصْبَعِي هَذِهِ وَفِي الْوُسْطَى وَالَّتِي تَلِيهَا .
also referenced under: Hadith 5287 (Reference) & Book 48, Hadith 248 (In-Book)