Sahih al-Bukhari 4706
Sahih al-Bukhari · Book 65: Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)) · The Statement of Allah "Who have made the Qur'an into parts (i.e., believed in one part and disbelieved in the other) ." (V.15:91)
Narrated Ibn `Abbas concerning:
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.
"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.