Anas bin Mālik reported that the Messenger of Allah ﷺ was heading somewhere and a man came to his side, so the Prophet ﷺ turned to him and said, “Shall I not inform you about the greatest (part) of the Quran? The man said, “Yes.” So he (the Prophet ﷺ) recited, Alhamdu lillāhi Rabbil ‘Ālameen (i.e., Sūrah Al-Fātiḥah). Reference: Sunan an-Nasāʾī al-Kubrā 8011, Ṣaḥīḥ Ibn Ḥibbān 774, and Mustadrak al-Ḥākim 2056 with slight variations