129. the Mother Book # 103The term "Mother Book" is generally used to designate the central Book of a religious Dispensation. In the Qur'an and Islamic Hadith, the term is used to describe the Qur'an itself. In the Babi Dispensation, the Bayan is the Mother Book, and the Kitab-i-Aqdas is the Mother Book of the Dispensation of Baha'u'llah. Further, the Guardian in a letter written on his behalf has stated that this concept can also be used as a "collective term indicating the body of the Teachings revealed by Baha'u'llah". This term is also used in a broader sense to signify the Divine Repository of Revelation.