"this and this are the same,": meaning the little finger and the thumb.
Sunan an-Nasa'i Book 45, Hadith 142
← Previous Hadith when the letter was found that was with the family of 'Amr bin Hazm, which they said the Messenger of Allah had written to them, they found in it, with regard to fingers, that the Diyahwas ten (Camels) for each.

Sunan an-Nasa'i Book 45, Hadith 141 Next Hadith → "This and this are the same: The little finger and the thumb (sahih)

Sunan an-Nasa'i Book 45, Hadith 143