Mishkat al-Masabih 2213
Ubayy b. Kā'b said:
When I was in the mosque a man entered and prayed and recited in a manner to which I objected. Afterwards a man entered and recited in a manner different from the other. When we had finished the prayer we all went to visit God’s messenger, and I said, “This man recited in a manner to which I objected and the other entered and recited in a manner different from his.” The Prophet then commanded them to recite, and when they had done so he expressed approval of both of them. This made me inclined to tell him he was wrong, even to an extent I had never reached in the pre-Islamic period; and when God’s messenger noticed how I was affected he gave me a pat on the chest, whereupon I broke into a sweat and was filled with fear as though I were looking at God. He then said to me, “A message was sent to me, Ubayy, to recite the Qur’ān in one mode, but when I replied that I wished matters to be made easy for my people, a second message instructed me to recite it in two modes. Again I replied that I wished matters to be made easy for my people, and a third message instructed me to recite it in seven modes, I being told at the same time that I might ask something for each reply I had received. I therefore said, ‘O God, forgive my people. O God, forgive my people;’ and I have delayed the third request till the day when all creatures, even including Abraham, seek my intercession."
 
Muslim transmitted it.
وَعَنْ أُبَيِّ بْنِ كَعْبٍ قَالَ: كُنْتُ فِي الْمَسْجِدِ فَدَخَلَ رَجُلٌ يُصَلِّي فَقَرَأَ قِرَاءَةً أَنْكَرْتُهَا عَلَيْهِ ثُمَّ دَخَلَ آخَرُ فَقَرَأَ قِرَاءَةً سِوَى قِرَاءَةِ صَاحِبِهِ فَلَمَّا قَضَيْنَا الصَّلَاةَ دَخَلْنَا جَمِيعًا عَلَى رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقُلْتُ إِنَّ هَذَا قَرَأَ قِرَاءَةً أَنْكَرْتُهَا عَلَيْهِ وَدخل آخر فَقَرَأَ سوى قِرَاءَة صَاحبه فَأَمَرَهُمَا النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَرَآ فَحَسَّنَ شَأْنَهُمَا فَسَقَطَ فِي نَفْسِي مِنَ التَّكْذِيبِ وَلَا إِذْ كُنْتُ فِي الْجَاهِلِيَّةِ فَلَمَّا رَأَى رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مَا قَدْ غَشِيَنِي ضَرَبَ فِي صَدْرِي فَفِضْت عَرَقًا وكأنما أنظر إِلَى الله عز وَجل فَرَقَا فَقَالَ لِي: «يَا أُبَيُّ أُرْسِلَ إِلَيَّ أَن اقْرَأِ الْقُرْآنَ عَلَى حَرْفٍ فَرَدَدْتُ إِلَيْهِ أَنْ هَوِّنْ عَلَى أُمَّتِي فَرَدَّ إِلَيَّ الثَّانِيَةَ اقْرَأْهُ عَلَى حَرْفَيْنِ فَرَدَّدَتْ إِلَيْهِ أَنْ هَوِّنْ عَلَى أُمَّتِي فَرَدَّ إِلَيَّ الثَّالِثَةِ اقْرَأْهُ عَلَى سَبْعَةِ أَحْرُفٍ وَلَكَ بِكُلِّ رَدَّةٍ رَدَدْتُكَهَا مَسْأَلَةٌ تَسْأَلُنِيهَا فَقُلْتُ اللَّهُمَّ اغْفِرْ لِأُمَّتِي اللَّهُمَّ اغْفِرْ لِأُمَّتِي وَأَخَّرْتُ الثَّالِثَةَ لِيَوْمٍ يَرْغَبُ إِلَيَّ الْخَلْقُ كُلُّهُمْ حَتَّى إِبْرَاهِيم صلى الله عَلَيْهِ وَسلم» . رَوَاهُ مُسلم