The Prophet (may Allah’s peace and blessings be upon him) did not know where Surahs were to be separated until "In the name of Allah, the Most Compassionate, the Most Merciful" was revealed to him
Authenticعَنِ ابْنِ عَبَّاسٍ رَضِيَ اللهُ عَنْهُمَا قَالَ: كَانَ النَّبِيُّ صَلَّى اللهُ عَليهِ وَسَلَّمَ لا يَعْرِفُ فَصْلَ السُّورةِ حَتَّى تَنْزِلَ عَليْهِ {بِسْمِ اللَّهِ الرَّحْمَنِ الرَّحِيمِ}.
Ibn ‘Abbās (may Allah be pleased with him) reported: The Prophet (may Allah’s peace and blessings be upon him) did not know where Surahs were to be separated until "In the name of Allah, the Most Compassionate, the Most Merciful" was revealed to him.
Explanation
Ibn ‘Abbās (may Allah be pleased with him) points out that the Qur’an's surahs would reveal to the Prophet (may Allah's peace and blessings be upon him) while he did not know where they should end and be separated, until "In the name of Allah, the Most Compassionate, the Most Merciful" was revealed to him; thereupon, he knew that the previous surah came to an end and this was the beginning of a new surah.
Benefits
- Basmalah "In the name of Allah, the Most Compassionate, the Most Merciful" separates between surahs, except between Surat al-Anfāl and Surat at-Tawbah.
Source · Narrated by Abu Dāwūd
From the Hadith Encyclopedia (hadeethenc.com).