It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "'All praise is for Allah, the Lord of all the worlds' [Surah al-Fatihah: 2], that is, Surah al-Fatihah, is seven verses, counting 'In the name of Allah, the Most Gracious, the Most Merciful' [Surah al-Fatihah: 1] with it, and it is the Seven Oft-Repeated (verses), Umm al-Qur'an and Surah al-Fatihah."
Abu Bakr al-Hanafi narrated it in the same way from Abdul-Hamid bin Ja'far, who said: Then I met Nuh and he narrated it to me from Sa'id from Abu Hurayrah as mawquf (his own statement), not marfu' (attributed to the Prophet). And what indicates this has been narrated to us from Ali, Ibn Abbas and others.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3956