Musnad Ahmad 26:358

Bahz narrated to us, Shu'bah narrated to us, 'Abd al-Malik ibn Maysarah narrated to me, he said: I heard an-Nazzal ibn Sabrah narrating from 'Abdullah, he said: I heard a man reciting a verse in a way other than how the Messenger of Allah (peace and blessings of Allah be upon him) had recited it to me. So I took him by the hand and brought him to the Prophet (peace and blessings of Allah be upon him). He said: "Both of you have done well." He said: And he became angry, until the anger was recognized in his face. Shu'bah said: My strongest assumption is that he said: "Do not differ, for those who were before you differed regarding it, and so they perished."