The Bayán, the Mother Book of the Bábi Dispensation, is the title given by the Báb to His Book of Laws, and it is also applied to the entire body of His Writings. The Persian Bayán is the major doctrinal work and principal repository of the laws ordained by the Báb. The Arabic Bayán is parallel in content but smaller and less weighty. When describing the Persian Bayán in God Passes By Shoghi Effendi indicated that it should be regarded "primarily as a eulogy of the Promised One rather than as a code of laws and ordinances designed to be a permanent guide to future generations".
'Abdu'l-Bahá has written: "The Bayán hath been superseded by the Kitáb-i-Aqdas, except in respect of such laws as have been confirmed and mentioned in the Kitáb-i-Aqdas."