Sahih Bukhari Volume 3, Book 41, Hadith Number 593.

Narated By ‘Abdullah : I heard a man reciting a verse (of the Holy Qur’an) but I had heard the Prophet reciting it differently. So, I caught hold of the man by the hand and took him to Allah’s Apostle who said, “Both of you are right.” Shu’ba, the sub-narrator said, “I think he said to them, “Don’t differ, for the nations before you differed and perished (because of their differences).”