It is narrated from Sayyiduna Samurah (may Allah be pleased with him); he says that the Messenger of Allah (peace and blessings be upon him) used to order us to recite the Noble Qur'an just as we had been taught it, and he said: "It has been revealed in three ahruf (modes of recitation). Do not differ over it and do not dispute about it, for it is blessed. So recite it just as you have been taught it."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 7002