Musnad Abu Ya'la al-Mawsili 152:194

Muhammad ibn Abi Bakr narrated to us, Khalid narrated to us, from Shu'bah, from 'Abd al-Malik ibn Maysarah, who said: I heard al-Nazzal, who said: I heard 'Abdullah say: I heard a man recite a verse from the Book of Allah that I had heard from the Messenger of Allah (may Allah bless him and grant him peace) differently. So I took him by the hand and brought him to the Prophet (may Allah bless him and grant him peace). I saw the face of the Prophet (may Allah bless him and grant him peace) change, and he said: "Both of you are doing well, so do not differ regarding it, for those who were before you differed regarding it," and he mentioned destruction.