I heard Hisham bin Hakim bin Hizam reciting Surat-al-Furqan in a way different to that of mine. Messenger of Allah ﷺ had taught it to me (in a different way). So, I was about to quarrel with him (during the prayer) but I waited till he finished, then I tied his garment round his neck and seized him by it and brought him to Messenger of Allah ﷺ and said, "I have heard him reciting Surat-al-Furqan in a way different to the way you taught it to me." The Prophet ﷺ ordered me to release him and asked Hisham to recite it. When he recited it, Allah s Apostle said, "It was revealed in this way." He then asked me to recite it. When I recited it, he said, "It was revealed in this way. The Qur'an has been revealed in seven different ways, so recite it in the way that is easier for you."  

سَمِعْتُ هِشَامَ بْنَ حَكِيمِ بْنِ حِزَامٍ يَقْرَأُ سُورَةَ الْفُرْقَانِ عَلَى غَيْرِ مَا أَقْرَؤُهَا وَكَانَ رَسُولُ اللَّهِ ﷺ أَقْرَأَنِيهَا وَكِدْتُ أَنْ أَعْجَلَ عَلَيْهِ ثُمَّ أَمْهَلْتُهُ حَتَّى انْصَرَفَ ثُمَّ لَبَّبْتُهُ بِرِدَائِهِ فَجِئْتُ بِهِ رَسُولَ اللَّهِ ﷺ فَقُلْتُ إِنِّي سَمِعْتُ هَذَا يَقْرَأُ عَلَى غَيْرِ مَا أَقْرَأْتَنِيهَا فَقَالَ لِي أَرْسِلْهُ ثُمَّ قَالَ لَهُ اقْرَأْ فَقَرَأَ قَالَ هَكَذَا أُنْزِلَتْ ثُمَّ قَالَ لِي اقْرَأْ فَقَرَأْتُ فَقَالَ هَكَذَا أُنْزِلَتْ إِنَّ الْقُرْآنَ أُنْزِلَ عَلَى سَبْعَةِ أَحْرُفٍ فَاقْرَءُوا مِنْهُ مَا تَيَسَّرَ  

Messenger of Allah ﷺ said, "Gabriel read the Qur'an to me in one way (i.e. dialect) and I continued asking him to read it in different ways till he read it in seven different ways."  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ أَقْرَأَنِي جِبْرِيلُ عَلَى حَرْفٍ فَلَمْ أَزَلْ أَسْتَزِيدُهُ حَتَّى انْتَهَى إِلَى سَبْعَةِ أَحْرُفٍ