Yahya related to me from Malik from al-Ala ibn Abd ar-Rahman ibnYaqub that Abu Said, the mawla of Amir ibn Kuraz told him that theMessenger of Allah, may Allah bless him and grant him peace, calledtoUbayy ibn Kab while he was praying. When Ubayy had finished hisprayer he joined the Messenger of Allah, may Allah bless him and granthim peace, and the Messenger of Allah put his hand upon his hand, andhe was intending to leave by the door of the mosque, so the Messengerof Allah, may Allah bless him and grant him peace, said, "I hope thatyou will not leave the mosque until you know a sura whose like Allahhas notsentdown in the Tawrah nor in the Injil nor in the Qur'an."Ubayysaid, "I began to slow down my pace in the hope of that. Then Isaid, 'Messenger of Allah, the sura you promised me!' He said, 'Whatdo you recite when you begin the prayer?' I recited the Fatiha (Sura 1) until I came to the end of it, and the Messengerof Allah, may Allahbless him and grant him peace, said, 'It is this sura, and it is the"seven oft-repeated" and the Great Qur'an which I was given.' "
App reference: Book 3, Hadith 39
USC-MSA web (English) reference: Book 3, Hadith 39
Arabic reference: Book 3, Hadith 186