"And indeed, there is among them a party who alter the Scripture with their tongues." Qatada's interpretation: They distorted the Book of Allah, introduced innovations into it, and claimed that it was from Allah.
﴿وَإِنَّ مِنْهُمْ لَفَرِيقًا يَلْوُونَ أَلْسِنَتَهُمْ بِالْكتاب﴾ تَفْسِير قَتَادَة: حرفوا كتاب الله، وابتدعوا فِيهِ، وَزَعَمُوا أَنه من عِنْد الله.