Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "The Qur'an has been revealed in seven ahruf, and disagreeing (or disputing) about the Qur'an is disbelief (kufr)" (he said this three times) "so when you come to know it, act upon it, and whatever you do not know, refer its ruling to the one who knows it."
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب التفسير / 11574
Hadith Gradingمحدثین:إسنادہ حسن
Hadith Takhrij«اخرجه ابو يعلى فى المسند (6016) اخرجه احمد فى المسند (7976) ، أخرجه مسند أحمد برقم: 7929، وأخرجه البحر الزخار المعروف بمسند البزار 10 - 18 برقم: 8579»