Narrated 'Umar bin Al-Khattab:

I heard Hisham bin Hakim reciting Surat Al-Furqan during the lifetime of Allah's Apostle and I listened to his recitation and noticed that he recited in several different ways which Allah's Apostle had not taught me. I was about to jump over him during his prayer, but I controlled my temper, and when he had completed his prayer, I put his upper garment around his neck and seized him by it and said, "Who taught you this Sura which I heard you reciting?" He replied, "Allah's Apostle taught it to me." I said, "You have told a lie, for Allah's Apostle has taught it to me in a different way from yours." So I dragged him to Allah's Apostle and said (to Allah's Apostle), "I heard this person reciting Surat Al-Furqan in a way which you haven't taught me!" On that Allah's Apostle ﷺ said, "Release him, (O 'Umar!) Recite, O Hisham!" Then he recited in the same way as I heard him reciting. Then Allah's Apostle ﷺ said, "It was revealed in this way," and added, "Recite, O 'Umar!" I recited it as he had taught me. Allah's Apostle then said, "It was revealed in this way. This Qur'an has been revealed to be recited in seven different ways, so recite of it whichever (way) is easier for you (or read as much of it as may be easy for you)."

حَدَّثَنَا سَعِيدُ بْنُ عُفَيْرٍ، قَالَ حَدَّثَنِي اللَّيْثُ، قَالَ حَدَّثَنِي عُقَيْلٌ، عَنِ ابْنِ شِهَابٍ، قَالَ حَدَّثَنِي عُرْوَةُ بْنُ الزُّبَيْرِ، أَنَّ الْمِسْوَرَ بْنَ مَخْرَمَةَ، وَعَبْدَ الرَّحْمَنِ بْنَ عَبْدٍ الْقَارِيَّ، حَدَّثَاهُ أَنَّهُمَا، سَمِعَا عُمَرَ بْنَ الْخَطَّابِ، يَقُولُ سَمِعْتُ هِشَامَ بْنَ حَكِيمٍ، يَقْرَأُ سُورَةَ الْفُرْقَانِ فِي حَيَاةِ رَسُولِ اللَّهِ ﷺ فَاسْتَمَعْتُ لِقِرَاءَتِهِ فَإِذَا هُوَ يَقْرَأُ عَلَى حُرُوفٍ كَثِيرَةٍ لَمْ يُقْرِئْنِيهَا رَسُولُ اللَّهِ ﷺ فَكِدْتُ أُسَاوِرُهُ فِي الصَّلاَةِ فَتَصَبَّرْتُ حَتَّى سَلَّمَ فَلَبَّبْتُهُ بِرِدَائِهِ فَقُلْتُ مَنْ أَقْرَأَكَ هَذِهِ السُّورَةَ الَّتِي سَمِعْتُكَ تَقْرَأُ. قَالَ أَقْرَأَنِيهَا رَسُولُ اللَّهِ ﷺ. فَقُلْتُ كَذَبْتَ فَإِنَّ رَسُولَ اللَّهِ ﷺ قَدْ أَقْرَأَنِيهَا عَلَى غَيْرِ مَا قَرَأْتَ، فَانْطَلَقْتُ بِهِ أَقُودُهُ إِلَى رَسُولِ اللَّهِ ﷺ فَقُلْتُ إِنِّي سَمِعْتُ هَذَا يَقْرَأُ بِسُورَةِ الْفُرْقَانِ عَلَى حُرُوفٍ لَمْ تُقْرِئْنِيهَا. فَقَالَ رَسُولُ اللَّهِ ﷺ " أَرْسِلْهُ اقْرَأْ يَا هِشَامُ ". فَقَرَأَ عَلَيْهِ الْقِرَاءَةَ الَّتِي سَمِعْتُهُ يَقْرَأُ. فَقَالَ رَسُولُ اللَّهِ ﷺ " كَذَلِكَ أُنْزِلَتْ ". ثُمَّ قَالَ " اقْرَأْ يَا عُمَرُ ". فَقَرَأْتُ الْقِرَاءَةَ الَّتِي أَقْرَأَنِي، فَقَالَ رَسُولُ اللَّهِ ﷺ " كَذَلِكَ أُنْزِلَتْ، إِنَّ هَذَا الْقُرْآنَ أُنْزِلَ عَلَى سَبْعَةِ أَحْرُفٍ فَاقْرَءُوا مَا تَيَسَّرَ مِنْهُ ".