Musnad Ahmad 658:45

'Affan narrated to us, Shu'bah narrated to us, from Abu Ishaq, who said: I heard Al-Bara' say: The first of the companions of the Messenger of Allah (may Allah bless him and grant him peace) to arrive to us were Mus'ab ibn 'Umayr and Ibn Umm Maktum. He said: They began to teach the people the Qur'an. Then 'Ammar, Bilal, and Sa'd came. He said: Then 'Umar ibn al-Khattab came with twenty [men]. Then the Messenger of Allah (may Allah bless him and grant him peace) came, and I have never seen the people of Medina rejoice over anything as they rejoiced over him, until I saw the young girls and the children saying: "This is the Messenger of Allah (may Allah bless him and grant him peace) who has come." He said: He did not arrive until I had recited "Glorify the name of your Lord, the Most High" [Surah Al-A'la] among the chapters of the Mufassal.