Narrated 'Umar bin Al-Khattab:
I passed by Hisham bin Hakim bin Hizam while he was reciting Surat Al-Furqan during the lifetime of the Messenger of Allah (ﷺ). I listened to his recitation and noticed that he recited it in several different ways, which the Messenger of Allah (ﷺ) had not taught me. I was about to jump over him during his Salat, but waited until he said the Salam. When he had said the Salam, I strangled him with his upper-garment and said: 'Who taught you this Surah which I heard you reciting?' He said: 'The Messenger of Allah (ﷺ) taught it to me.' I said to him: 'You lie! By Allah! The Messenger of Allah (ﷺ) taught me this Surah which you were reciting.' I dragged him to the Messenger of Allah (ﷺ) and said: 'O Messenger of Allah! I heard this one reciting Surat Al-Furqan in a manner different from how you taught me, and you taught me Surat Al-Furqan.' The Prophet (ﷺ) said: 'Release him O 'Umar! Recite O Hisham.' So he recited it for him as I had heard him reciting. Then the Prophet (ﷺ) said to me: 'This is how it was revealed.' Then the Prophet (ﷺ) said to me, 'Recite O 'Umar.' So I recited the recitation which the Prophet (ﷺ) taught me. The Prophet (ﷺ) said: 'This is how it was revealed.' Then the Prophet (ﷺ) said 'Indeed this Qur'an was revealed in seven modes, so recite of it what is easier for you.'