(44, 45) باب عَقْلِ الأَصَابِعِ
It was narrated from Ibn 'Abbas:
"This and this are the same: The little finger and the thumb (sahih)
Reference: Sunan an-Nasa'i 4848
In-book reference: Book 45, Hadith 143
English translation: Vol. 5, Book 45, Hadith 4852