ON THE SUBJECT OF 183 RECITATION OF EXTRA SPECIAL CHAPTERS AND VERSES; AL FATIHAH H 1023 "The Prophet, praise and peace be upon him, said to me (Abu Sa'id Rafi'), 'May I teach you before you go out of the Mosque which is the greatest chapter of the Koran?' Then he grasped hold of my hand. As we were leaving the Mosque I said to him, 'O Messenger of Allah, praise and peace be upon him, you said you would teach me which is the greatest chapter of the Koran.' He replied, 'Praise be to Allah, the Lord of the Worlds..." (Ch.1 Al Fatihah) it is the seven dual verses and the Great Koran which I was given.'" R 1023 Bukhari with a chain up to Abu Sa'id Rafi' who related that the Messenger of Allah, praise and peace be upon him, said this.
باب الحث عَلَى سور وآيات مخصوصة 1009- عن أَبي سَعِيدٍ رَافِعِ بن الْمُعَلَّى رضي الله عنه ، قَالَ : قَالَ لي رسولُ اللهِ صلى الله عليه وآله وسلم : "أَلاَ أُعَلِّمُكَ أَعْظَمَ سُورَةٍ في القُرْآن قَبْلَ أنْ تَخْرُجَ مِنَ الْمَسْجِدِ ؟" فَأخَذَ بِيَدِي ، فَلَمَّا أرَدْنَا أنْ نَخْرُجَ ، قُلْتُ : يَا رَسُولَ اللهِ ، إنَّكَ قُلْتَ : لأُعَلِّمَنَّكَ أعْظَمَ سُورَةٍ في القُرْآنِ ؟ قَالَ : "الحَمْدُ للهِ رَبِّ العَالَمِينَ ، هِيَ السَّبْعُ المَثَانِي وَالقُرْآنُ العَظِيمُ الَّذِي أُوتِيتُهُ" رواه البخاري .