Sahih al-Bukhari 5062
Narrated `Abdullah:
That he heard a man reciting a Quranic Verse which he had heard the Prophet (ﷺ) reciting in a different way. So he took that man to the Prophet (and told him the story). The Prophet (ﷺ) said, "Both of you are reciting in a correct way, so carry on reciting." The Prophet (ﷺ) further added, "The nations which were before you were destroyed (by Allah) because they differed."
حَدَّثَنَا سُلَيْمَانُ بْنُ حَرْبٍ، حَدَّثَنَا شُعْبَةُ، عَنْ عَبْدِ الْمَلِكِ بْنِ مَيْسَرَةَ، عَنِ النَّزَّالِ بْنِ سَبْرَةَ، عَنْ عَبْدِ اللَّهِ، أَنَّهُ سَمِعَ رَجُلاً، يَقْرَأُ آيَةً، سَمِعَ النَّبِيَّ صلى الله عليه وسلم خِلاَفَهَا، فَأَخَذْتُ بِيَدِهِ فَانْطَلَقْتُ بِهِ إِلَى النَّبِيِّ صلى الله عليه وسلم فَقَالَ ‏
"‏ كِلاَكُمَا مُحْسِنٌ فَاقْرَآ ـ أَكْبَرُ عِلْمِي قَالَ ـ فَإِنَّ مَنْ كَانَ قَبْلَكُمُ اخْتَلَفُوا فَأَهْلَكَهُمْ ‏"‏‏.‏