Sahih al-Bukhari 4941
Narrated Al-Bara:
The first of the companions of the Prophet (ﷺ) who came to us (in Medina), were Mus`ab bin `Umar and 
Ibn Um Maktum, and they started teaching us the Qur'an. Then came `Ammar, Bilal and Sa`d. 
Afterwards `Umar bin Al-Kkattab came along with a batch of twenty (men): and after that the Prophet (ﷺ) 
came. I never saw the people of Medina so pleased with anything as they were with his arrival, so that 
even the little boys and girls were saying, "This is Allah's Messenger (ﷺ) who has come." He (the Prophet (ﷺ) ) 
did not come (to Medina) till I had learnt Surat Al-Ala and also other similar Suras.
حَدَّثَنَا عَبْدَانُ، قَالَ أَخْبَرَنِي أَبِي، عَنْ شُعْبَةَ، عَنْ أَبِي إِسْحَاقَ، عَنِ الْبَرَاءِ ـ رضى الله عنه ـ قَالَ أَوَّلُ مَنْ قَدِمَ عَلَيْنَا مِنْ أَصْحَابِ النَّبِيِّ صلى الله عليه وسلم مُصْعَبُ بْنُ عُمَيْرٍ وَابْنُ أُمِّ مَكْتُومٍ فَجَعَلاَ يُقْرِئَانِنَا الْقُرْآنَ، ثُمَّ جَاءَ عَمَّارٌ وَبِلاَلٌ وَسَعْدٌ ثُمَّ جَاءَ عُمَرُ بْنُ الْخَطَّابِ فِي عِشْرِينَ ثُمَّ جَاءَ النَّبِيُّ صلى الله عليه وسلم فَمَا رَأَيْتُ أَهْلَ الْمَدِينَةِ فَرِحُوا بِشَىْءٍ فَرَحَهُمْ بِهِ، حَتَّى رَأَيْتُ الْوَلاَئِدَ وَالصِّبْيَانَ يَقُولُونَ هَذَا رَسُولُ اللَّهِ قَدْ جَاءَ‏.‏ فَمَا جَاءَ حَتَّى قَرَأْتُ ‏{‏سَبِّحِ اسْمَ رَبِّكَ الأَعْلَى‏}‏ فِي سُوَرٍ مِثْلِهَا‏.‏