'Ali said: "The Messenger of Allah said to me: 'O 'Ali, ask Allah for guidance and steadfastness,' and he forbade me from placing a ring on this one and this one' - and he pointed to his forefinger and middle finger.
Sunan an-Nasa'i Book 48, Hadith 171
← Previous Hadith "The Messenger of Allah said: 'Do not be so close to the Mushrikin that you can benefit from the light of their fires, and do not engrave Arabic (words) on your rings.'"

Sunan an-Nasa'i Book 48, Hadith 170 Next Hadith → "The Messenger of Allah forbade me to wear a ring on this one and this one," meaning the forefinger and middle finger. And this is the wording of Ibn Al-Muthanna.

Sunan an-Nasa'i Book 48, Hadith 172