Sahih al-Bukhari 4995
Book 66: Virtues of the Qur'an · Narrated by Al-Bara'
Arabic
حَدَّثَنَا أَبُو الْوَلِيدِ، حَدَّثَنَا شُعْبَةُ، أَنْبَأَنَا أَبُو إِسْحَاقَ، سَمِعَ الْبَرَاءَ ـ رضى الله عنه ـ قَالَ تَعَلَّمْتُ {سَبِّحِ اسْمَ رَبِّكَ} قَبْلَ أَنْ يَقْدَمَ النَّبِيُّ صلى الله عليه وسلم.
English translation
Narrated Al-Bara':I learnt, 'Glorify the Name of your Lord the Most High' (Surat al-A'la) No 87, before the Prophet (ﷺ) came (to Medina)
Reference: Sahih al-Bukhari 4995, Book of Virtues of the Qur'an. English translation by Dr. Muhammad Muhsin Khan.