The Declaration of Bahá’u’lláh is celebrated annually by the twelve-day Ridván Festival, described by Shoghi Effendi as "the holiest and most significant of all Bahá’í festivals" (see notes 138 and 140).
108. the Bayán [#77]
The Bayán, the Mother Book of the Bábí 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‘Abdu’l-Bahá has written: "The Bayán hath been superseded by the Kitáb-i-Aqdas, except in respect of such laws as have been confirmed and mentioned in the Kitáb-i-Aqdas."
109. the destruction of books [#77]
In the Tablet of Is̱ẖráqát Bahá’u’lláh, referring to the fact that the Báb had made the laws of the Bayán subject to His sanction, states that He put some of the Báb’s laws into effect "by embodying them in the Kitáb-i-Aqdas in different words", while others He set aside.
With regard to the destruction of books, the Bayán commanded the Báb’s followers to destroy all books except those that were written in vindication of the Cause and Religion of God. Bahá’u’lláh abrogates this specific law of the Bayán.
As to the nature and severity of the laws of the Bayán, Shoghi Effendi in a letter written on his behalf provides the following comment: