Bai'at or Bay'ah (Arabic: بَيْعَة; pledge, initiation; literally a "sale" or a "transaction") is an Islamic practice of declaring on oath, one's allegiance to a particular leader.
The Bay'ah comprises the shahadah, prayers of repentance and a promise to abide by the ten conditions stipulated by Mirza Ghulam Ahmad for joining the Community.
The tradition was originally started by the Islamic prophet Muhammad and continued by the Rightly Guided Caliphs.
Mirza Ghulam Ahmad, after claiming to be divinely appointed as the Mujaddid of Islam, took the first bay'ah in 1889 at Ludhiana.
The oath includes the shahadah, prayers of repentance and a promise to abide by the ten conditions of Bai'at.
At the end, all members of the congregation, which includes those participating around the world, prostrate themselves as an expression of gratitude to God.