Depend on few valid Ahādīth, بسم الله الرحمن الرحيم is actually the first verse of every Sūrah.
“Qutaybah ibn Sa‘īd, Ahmad ibn Muhammad al-Marwazī, and Ibn as-Sarh narrated to us; from Sa‘īd ibn Jubayr, Qutaybah said; from Haḍrat Ibn ‘Abbās(ra), he said: The Holy Prophet(SAW) used to not know the separation of Sūrah until Bismi-Llāh ar-Rahmān ar-Rahīm descended to him”.
[Sunan Abī Dāwūd, Kitāb aṣ-Ṣalāt, Bāb al-Jahr Bi Bismi-Llāh ar-Rahmān ar-Rahīm, no. 788].
Elaboration: This Hadīth is Mursal Ṣahābī from Haḍrat Ibn ‘Abbās(ra). The law of Hadīth Mursal, in its origin, according to the populary scholars of Uṣūl and Fiqh, is Ḍa‘īf Mardūd. But, the scholars disagree with each others on the law of basing argument on Hadīth Mursal. There are three opinions on it:
1. Ḍa‘īf Mardūd.
This is held by the popularly scholars of Hadīth and Fiqh.
2. Ṣahīh, we must base argument on it.
This is held by al-Imām Abū Hanīfah(rh), …continue reading at nafirizaman.blogspot.in