Sahih Muslim
Sahih Muslim 818 c
The clarification that the Qur’an was revealed in seven ahruf (modes of recitation), and clarifying its meaning
Arabic hadith text
حَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، وَعَبْدُ بْنُ حُمَيْدٍ، قَالاَ أَخْبَرَنَا عَبْدُ الرَّزَّاقِ، أَخْبَرَنَا مَعْمَرٌ، عَنِ الزُّهْرِيِّ، كَرِوَايَةِ يُونُسَ بِإِسْنَادِهِ
Translation
This hadith has been transmitted by Zuhri.