Al-Ansar Pass, situated between two mountains in Mina, is known as the place where 12 men from the Aws and Khazraj tribes pledged allegiance to Prophet Muhammad (peace be upon him). The mountains are an extension of Mount Thabir.
According to Dr. Fawaz Al-Dahhas, director of the Makkah History Center, the 12 men arranged a meeting with the Prophet at the pass in response to his call for tribes to believe in one God and abandon the worship of idols. There, they swore their allegiance to him, and promised to spread the teachings of Islam, in what became known as “the First Pledge of Al-Aqabah.”
Prophet Muhammad sent Mus’ab ibn Umair along with these 12 men to carry out missionary activity in Madinah, and the following year, 72 people came and swore loyalty to the Prophet, in what became known as the “the Second Pledge of Al-Aqabah.”
In 144H (761/762 A.D.), Caliph Abu Ja’far Al-Mansur ordered the construction of the Bay’ah Mosque (Mosque of the Pledge), which overlooks Mina in the southern foothills of Mount Thabir, which opens out over Al-Ansar Pass.
The mosque contains a stone with “Abdullah — Commander of the Caliph — ordered the building of this mosque” written on it, referring to the Abbassid Caliph.
The mosque includes two hallways, which are 23 cubits (approximately 10.5 meters) long and 14.5 cubits wide, each covered with three domes and four arches, in addition to two doors. The mosque is around 38 cubits long, from its mihrab to the end of the courtyard.