Those who have made their Scripture into parts are the people of the Scripture who divided it into portions and believed in a part of it and disbelieved the other.
هُمْ أَهْلُ الْكِتَابِ جَزَّءُوهُ أَجْزَاءً فَآمَنُوا بِبَعْضِهِ وَكَفَرُوا بِبَعْضِهِ
They, the people of the Scriptures, divided this Scripture into parts, believing in some portions of it and disbelieving the others. (See 15:91)
هُمْ أَهْلُ الْكِتَابِ جَزَّءُوهُ أَجْزَاءً فَآمَنُوا بِبَعْضِهِ وَكَفَرُوا بِبَعْضِهِ {يَعْنِي قَوْلَ اللَّهِ تَعَالَى {الَّذِينَ جَعَلُوا الْقُرْآنَ عِضِينَ }