These are the ordinances of God that have been set down in the Books and Tablets by His Most Exalted Pen. Hold ye fast unto His statutes and commandments, and be not of those who, following their idle fancies and vain imaginings, have clung to the standards fixed by their own selves, and cast behind their backs the standards laid down by God. Abstain from food and drink from sunrise to sundown, and beware lest desire deprive you of this grace that is appointed in the Book.

Ye have been forbidden to commit murder or adultery, or to engage in backbiting or calumny; shun ye, then, what hath been prohibited in the holy Books and Tablets.

Recite ye the verses of God every morn and eventide. Whoso faileth to recite them hath not been faithful to the Covenant of God and His Testament, and whoso turneth away from these holy verses in this Day is of those who throughout eternity have turned away from God. Fear ye God, O My servants, one and all. Pride not yourselves on much reading of the verses or on a multitude of pious acts by night and day; for were a man to read a single verse with joy and radiance it would be better for him than to read with lassitude all the Holy Books of God, the Help in Peril, the Self-Subsisting. Read ye the sacred verses in such measure that ye be not overcome by languor and despondency. Lay not upon your souls that which will weary them and weigh them down, but rather what will lighten and uplift them, so that they may soar on the wings of the Divine verses towards the Dawning-place of His manifest signs; this will draw you nearer to God, did ye but comprehend.

Whoso hath not recognized this sublime and fundamental verity, and hath failed to attain this most exalted station, the winds of doubt will agitate him, and the sayings of the infidels will distract his soul. He that hath acknowledged this principle will be endowed with the most perfect constancy. All honour to this all-glorious station, the remembrance of which adorneth every exalted Tablet. Such is the teaching which God bestoweth on you, a teaching that will deliver you from all manner of doubt and perplexity, and enable you to attain unto salvation in both this world and in the next. He, verily, is the Ever-Forgiving, the Most Bountiful. He it is Who hath sent forth the Messengers, and sent down the Books to proclaim "There is none other God but Me, the Almighty, the All-Wise".

the Mother Book
The term "Mother Book" is generally used to designate the central Book of a religious Dispensation. In the Qur’án and Islamic Hadí­th, the term is used to describe the Qur’án itself. In the Bábí­ Dispensation, the Bayán is the Mother Book, and the Kitáb-i-Aqdas is the Mother Book of the Dispensation of Bahá’u’lláh. 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 Bahá’u’lláh". This term is also used in a broader sense to signify the Divine Repository of Revelation.

Take heed lest ye be prevented by aught that hath been recorded in the Book from hearkening unto this, the Living Book
The “Book” is the record of the revealed Word of the Manifestations of God. The “Living Book” is a reference to the Person of the Manifestation.
These words contain an allusion to a statement of the Báb in the Persian Bayán about the “Living Book”, which He identifies as Him Whom God will make manifest. In one of His Tablets Bahá’u’lláh Himself states: “The Book of God hath been sent down in the form of this Youth.”
In this verse of the Aqdas, and again in paragraph 168 of the Aqdas, Bahá’u’lláh refers to Himself as the “Living Book”. He cautions the “followers of every other Faith” against seeking “reasons in their Holy Books” for refuting the utterances of the “Living Book”. He admonishes the people not to allow what has been recorded in the “Book” to prevent them from recognising His Station and from holding fast to what is in this new Revelation.