Sahih al-Bukhari, Volume 6, Book 60, Hadith 229 (USC-MSA) ⓘ
Narrated Ibn `Abbas concerning: "As We have sent down (the Scripture) on those who are divided (Jews and Christians)." (15.90) They believed in part of it and disbelieved in the other, (and they) are the Jews and the Christians.
حَدَّثَنِي عُبَيْدُ اللَّهِ بْنُ مُوسَى، عَنِ الأَعْمَشِ، عَنْ أَبِي ظَبْيَانَ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ {كَمَا أَنْزَلْنَا عَلَى الْمُقْتَسِمِينَ} قَالَ آمَنُوا بِبَعْضٍ وَكَفَرُوا بِبَعْضٍ، الْيَهُودُ وَالنَّصَارَى.
also referenced under: Book 65, Hadith 4706 (In-Book) & Hadith 4706 (DarusSalam)