Sūrat al-Fatiha, no.1. Revealed in Makkah and Madinah, 7 verses.
This Sūra is the first complete Sūra to be revealed to the Prophet (s). It is known as Ummul Kitab, or mother of the book. The word al-Fatiha means the opening, as it is the Sūra with which the Quran opens. Sūra al-Fatiha was revealed twice, once in Makkah and then again in Madinah, and is thus known al-Mathani.
Merits of reciting the Sūra
There are very many merits of this Sūra. Imam Ali (a) quotes the Prophet (s) as saying that it is a treasure in the Divine Throne (Arsh), which has exclusively been given to the Prophet (s). Jibaril told the Prophet (s) that this Sūra prevented punishment of Allah from coming down on the Muslim nation. It is also a Sūra of healing.