Sahih Muslim 820
Sahih Muslim · Book 6: The Book of Prayer - Travellers · The clarification that the Qur’an was revealed in seven ahruf (modes of recitation), and clarifying its meaning
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ ، حَدَّثَنَا مُحَمَّدُ بْنُ بِشْرٍ ، حَدَّثَنِي إِسْمَاعِيلُ بْنُ أَبِي، خَالِدٍ حَدَّثَنِي عَبْدُ اللَّهِ بْنُ عِيسَى ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبِي لَيْلَى ، أَخْبَرَنِي أُبَىُّ بْنُ كَعْبٍ ، أَنَّهُ كَانَ جَالِسًا فِي الْمَسْجِدِ إِذْ دَخَلَ رَجُلٌ فَصَلَّى فَقَرَأَ قِرَاءَةً وَاقْتَصَّ الْحَدِيثَ بِمِثْلِ حَدِيثِ ابْنِ نُمَيْرٍ .
Ubayy b. Ka'b reported that he was sitting in a mosque that a person entered it and he observed prayer, and made recitation, the rest of the hadith is the same.