Sunan an-Nasa'i 4847
سنن النسائي#4847Sahihأَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا شُعْبَةُ، قَالَ حَدَّثَنِي قَتَادَةُ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، رضى الله عنهما عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " هَذِهِ وَهَذِهِ سَوَاءٌ " . يَعْنِي الْخِنْصَرَ وَالإِبْهَامَ .
It was narrated from Ibn 'Abbas that the Propher said:"this and this are the same,": meaning the little finger and the thumb
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih Bukhari
In-book reference: 45:142