Mishkat al-MasabihChapter 8Hadith 2121
Full Sharh — Mishkat al-Masabih 2121
وَعَنِ ابْنِ عَبَّاسٍ قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ لَا يَعْرِفُ فَصْلَ السُّورَةِ حَتَّى يَنْزِلَ عَلَيْهِ بِسْمِ اللَّهِ الرَّحْمَنِ الرَّحِيم. رَوَاهُ أَبُو دَاوُد
English Translation
Ibn ‘Abbās said that God's messenger did not know where sūras were to be separated till “In the name of God, the Compassionate, the Merciful,” was sent down. Abū Dāwūd transmitted it.
Source
Mishkat al-Masabih(مشكاة المصابيح)
The Excellent Qualities of the Qur'an
Hadith Number
2121