How were the Surahs of the Holy Quran named, and how were they arranged?

The names of the Surahs were known and circulated during the time of the Prophet, peace and blessings be upon him, and many hadiths indicate this, such as the hadith of Ibn Abbas asking Uthman about the placement of Surat Bara'ah and Al-Anfal. The Prophet, peace and blessings be upon him, also referred to the names of Surahs in other hadiths, such as his saying about Al-Baqarah and Al Imran. It is most likely that the naming of the Surahs was by divine injunction from him, peace and blessings be upon him.

As for the order of the Surahs in the Mushaf, scholars differed on this. The majority held that it was an ijtihad (independent reasoning) by the Companions, inspired by the Prophet's recitation, peace and blessings be upon him, while others held that it was by divine injunction from him, peace and blessings be upon him. It is likely that the difference is semantic, as both opinions hold that the order of the Surahs ultimately goes back to the Prophet, peace and blessings be upon him, either by verbal injunction or practical attribution. Some tend to believe that the order of many Surahs was known during his lifetime, and for what was not, the matter was entrusted to the Ummah.

The hadith of Hudhayfah Al-Thaqafi about the Prophet's division of the Qur'an into hizbs, and the Companions' division of it into three, five, seven, nine, eleven, thirteen, and the hizb of Al-Mufassal, indicates that this order was known during his time, peace and blessings be upon him.