Musannaf Ibn Abi Shayba 18:262

Abu Bakr narrated to us, he said: Muhammad ibn Abi ‘Adi narrated to us, he said: I found in a book from Humayd, from Bakr, from Hisham ibn Hubayrah, that Ibn ‘Umar and Ibn ‘Abbas both said: "The fingers are equal, and this and this are equal."