It was narrated that Abu Saeed bin Mualla said: "The Messenger of Allah( ﷺ saw) said to me: Shall I not teach you the greatest Surah in the Quran before I leave the Masjid? Then the Prophet(saw) went to leave, so I reminded him, and he said: AI-hamdu Iillahi Rab-il-Alamin(All the praise is to Allah, the Lord of all that exists). It is the Seven Oft-Recited Verses, and it is the Grand Quran that has been given to me." (Sahih)