I heard Hisham bin Hakim reciting Surat-al-Furqan during the lifetime of Messenger of Allah ﷺ, I listened to his recitation and noticed that he was reciting in a way that Messenger of Allah ﷺ had not taught me. I was about to jump over him while He was still in prayer, but I waited patiently and when he finished his prayer, I put my sheet round his neck (and pulled him) and said, "Who has taught you this Sura which I have heard you reciting?" Hisham said, "Messenger of Allah ﷺ taught it to me." I said, "You are telling a lie, for he taught it to me in a way different from the way you have recited it!" Then I started leading (dragged) him to Messenger of Allah ﷺ and said (to the Prophet), " I have heard this man reciting Surat-al- Furqan in a way that you have not taught me." The Prophet ﷺ said: "(O ʿUmar) release him! Recite, O Hisham." Hisham recited in the way I heard him reciting. Messenger of Allah ﷺ said, "It was revealed like this." Then Messenger of Allah ﷺ said, "Recite, O ʿUmar!" I recited in the way he had taught me, whereupon he said, "It was revealed like this," and added, "The Qur'an has been revealed to be recited in seven different ways, so recite of it whichever is easy for you ." (See Hadith No. 514, Vol. 6)  

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 فَلَبَبْتُهُ بِرِدَائِهِ فَقُلْتُ مَنْ أَقْرَأَكَ هَذِهِ السُّورَةَ الَّتِي سَمِعْتُكَ تَقْرَأُ قَالَ أَقْرَأَنِيهَا رَسُولُ اللَّهِ ﷺ فَقُلْتُ كَذَبْتَ أَقْرَأَنِيهَا عَلَى غَيْرِ مَا قَرَأْتَ فَانْطَلَقْتُ بِهِ أَقُودُهُ إِلَى رَسُولِ اللَّهِ ﷺ فَقُلْتُ إِنِّي سَمِعْتُ هَذَا يَقْرَأُ سُورَةَ الْفُرْقَانِ عَلَى حُرُوفٍ لَمْ تُقْرِئْنِيهَا فَقَالَ أَرْسِلْهُ اقْرَأْ يَا هِشَامُ فَقَرَأَ الْقِرَاءَةَ الَّتِي سَمِعْتُهُ فَقَالَ رَسُولُ اللَّهِ ﷺ كَذَلِكَ أُنْزِلَتْ ثُمَّ قَالَ رَسُولُ اللَّهِ ﷺ اقْرَأْ يَا عُمَرُ فَقَرَأْتُ الَّتِي أَقْرَأَنِي فَقَالَ كَذَلِكَ أُنْزِلَتْ إِنَّ هَذَا الْقُرْآنَ أُنْزِلَ عَلَى سَبْعَةِ أَحْرُفٍ فَاقْرَءُوا مَا تَيَسَّرَ مِنْهُ