It was narrated that Abu Sa'eed bin Mu'alla said:"The Messenger of Allah(ﷺ) said to me: 'Shall I not teach you the greatest Surah in the QUran before I leave the masjid?' Then the Propeht(ﷺ) went to leave, so I reminded him, and he said: Al-hamdulillahi Rabbil-Alameen (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

English translation · Sunan Ibn Majah