The Book of Adornment
48/52. Chapter:
Prohibition of Wearing the Ring on the Forefinger
Sunan an-Nasai
أَخْبَرَنَا مُحَمَّدُ بْنُ مَنْصُورٍ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ عَاصِمِ بْنِ كُلَيْبٍ، عَنْ أَبِي بُرْدَةَ، قَالَ قَالَ عَلِيٌّ قَالَ لِي رَسُولُ اللَّهِ صلى الله عليه وسلم " يَا عَلِيُّ سَلِ اللَّهَ الْهُدَى وَالسَّدَادَ " . وَنَهَانِي أَنْ أَجْعَلَ الْخَاتَمَ فِي هَذِهِ وَهَذِهِ . وَأَشَارَ يَعْنِي بِالسَّبَّابَةِ وَالْوُسْطَى .
It was narrated that Abu Burdah said: 'Ali said: "The Messenger of Allah [SAW] 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.
Reference : Sunan an-Nasa'i 5210In-book reference : Book 48, Hadith 171English translation : Vol. 6, Book 48, Hadith 5213