As regards the translation and publication of the Bayan, there are laws in the Bayan which have been abrogated by the Kitáb-i-Aqdas and the Bahá’ísare bound by the laws of the Kitáb-i-Aqdas. Were the Bayan to be published and translated, the peoples of the other countries—and indeed even the Persians—would think that the basis of the religion of the Bahá’ís was those severe laws which are found in the Bayan. Whereas according to the explicit text of the Kitáb-i-Aqdas those laws are not applicable. Therefore, the Bayan must be published in all parts and corners of the world after the publication of the Kitáb-i-Aqdas, so that readers may know that those severe laws have been abrogated and canceled. Before the publication of the Kitáb-i-Aqdas and its translation, and before its laws become well
known, the publication of the Bayan is not permissible.
(‘Abdu’l-Bahá, Ma‘ida-yi Asmani", vol 2., p.16-7; provisional translation by Ahang Rabbani, received 27 December 1994)

Beware lest aught that hath been revealed in the Bayan should keep you from your Lord, the Most Compassionate. God is My witness that the Bayan was sent down for no other purpose than to celebrate My praise, did ye but know! In it the pure in heart will find only the fragrance of My love, only My Name that overshadoweth all that seeth and is seen. Say: Turn ye, O people, unto that which hath proceeded from My Most Exalted Pen. Should ye inhale therefrom the fragrance of God, set not yourselves against Him, nor deny yourselves a portion of His gracious favour and His manifold bestowals. Thus doth your Lord admonish you; He, verily, is the Counsellor, the Omniscient.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 84)

Exemption from obligatory prayer and fasting is granted to women who are menstruating; they should, instead, perform their ablutions (see note 34) and repeat 95 times a day between one noon and the next, the verse “Glorified be God, the Lord of Splendour and Beauty”. This provision has its antecedent in the Arabic Bayan, where a similar dispensation was granted. In some earlier religious Dispensations, women in their courses were considered ritually unclean and were forbidden to observe the duties of prayer and fasting. The concept of ritual uncleanness has been abolished by Bahá’u’lláh.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 173)

God hath relieved you of the ordinance laid down in the Bayan concerning the destruction of books. We have permitted you to read such sciences as are profitable unto you, not such as end in idle disputation; better is this for you, if ye be of them that comprehend.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 47)

In some earlier religious Dispensations, the wearing of the hair of certain animals or having certain other objects on one’s person was held to invalidate one’s prayer. Bahá’u’lláh here confirms the Báb’s pronouncement in the Arabic Bayán that such things do not invalidate one’s prayer.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 170)

In the Arabic Bayan the Báb called upon the believers to lay their foreheads on surfaces of crystal when prostrating. Similarly, in Islam, certain restrictions are imposed with regard to the surface on which Muslims are permitted to prostrate. Bahá’u’lláh abrogates such restrictions and simply specifies “any surface that is clean”.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 171)

In the Arabic Bayan the Báb described His inheritance law as being “in accordance with a hidden knowledge in the Book of God—a knowledge that shall never change or be replaced”. He also stated that the numbers by which the division of the inheritance was expressed had been invested with a significance intended to aid in the recognition of Him Whom God will make manifest.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 188)

In the Bayan it had been forbidden you to ask Us questions. The Lord hath now relieved you of this prohibition, that ye may be free to ask what you need to ask, but not such idle questions as those on which the men of former times were wont to dwell. Fear God, and be ye of the righteous! Ask ye that which shall be of profit to you in the Cause of God and His dominion, for the portals of His tender compassion have been opened
before all who dwell in heaven and on earth.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 64)

In the Bayan the Báb allowed the use of gold and silver utensils, thus abrogating the Islamic condemnation of their use which stems not from an explicit injunction of the Qur‘án but from Muslim traditions. Bahá’u’lláh here confirms the Báb’s ruling.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 198)

In the Bayan the Báb says that every religion of the past was fit to become universal. The only reason why the failed to attain that mark was the incompetence of their followers. He then proceeds to give a definite promise that this would not be the fate of the Revelation of ‘Him Whom God would make manifest‘, that it will become universal and include all the people of the world. This shows that we will ultimately succeed. But could we not through our shortcomings, failures to sacrifice and reluctance to concentrate our efforts in spreading the Cause, retard the realization of that ideal. And what would that mean? It shall mean that we will be held responsible before God, that the race will remain longer in its state of waywardness, that wars would not be soon averted, that human suffering will last longer.
(Shoghi Effendi, Lights of Guidance, p. 469)

In the Bayan, the Báb enjoined the ordinance of pilgrimage once in a lifetime upon those of His followers who were financially able to undertake the journey. He stated that the obligation was not binding on women in order to spare them the rigours of travel. Bahá’u’lláh likewise exempts women from His pilgrimage requirements. The Universal House of Justice has clarified that this exemption is not a prohibition, and that women are free to perform the pilgrimage.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 191)

It hath been laid down in the Bayan that marriage is dependent upon the consent of both parties. Desiring to establish love, unity and harmony amidst Our servants, We have conditioned it, once the couple’s wish is known, upon the permission of their parents, lest enmity and rancour should arise amongst them. And in this We have yet other purposes. Thus hath Our commandment been ordained.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 42)

Just as the Bayan had been revealed by the Báb at about the mid-point of His Ministry, Bahá’u’lláh revealed the Kitáb-i-Aqdas around 1873, some twenty years after He had received, in the Siyah-Chal of Tihran, the intimation of His Revelation.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 8)

O people of the Bayan, I adjure you by your Lord, the God of mercy, to look with the eye of fairness upon this utterance which hath been sent down through the power of truth, and not to be of those who see the testimony of God yet reject and deny it. They, in truth, are of those who will assuredly perish. The Point of the Bayan hath explicitly made mention in this verse of the exaltation of My Cause before His own Cause; unto this will testify every just and understanding mind. As ye can readily witness in this day, its exaltation is such as none can deny save those whose eyes are drunken in this mortal life and whom a humiliating chastisement awaiteth in the life to come.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 69)

Shoghi Effendi feels that the unity of the Bahá’í Revelation as one complete whole embracing the Faith of the Báb should be emphasized... The Faith of the Báb should not be divorced from that of Bahá’u’lláh. Though the teachings of the Bayan have been abrogated and superseded by the laws of the Aqdas, yet due to the fact that the Báb considered Himself as the Forerunner of Bahá’u’lláh, we would regard His Dispensation together with that of Bahá’u’lláh as forming one entity, the former being introductory to the advent of the latter.
(Kitáb-i-Aqdas, pp.7-8)

The Báb introduced a new calendar, known now as the Badi’ or Bahá’í calendar (see notes 27 and 147). According to this calendar, a day is the period from sunset to sunset. In the Bayan, the Báb ordained the month of Ala’ to be the month of fasting, decreed that the day of Naw-Ruz should mark the termination of that period, and designated Naw-Ruz as the Day of God. Bahá’u’lláh confirms the Badi’ calendar wherein Naw-Ruz is designated as a feast.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 177)

The Báb specified that the ‘Bayan is not completed and that ‘He Whom God would manifest’ (Bahá’u’lláh) would complete it, though not in the actual form, but only spiritually in the form of another book. The qán is believed to be its continuation.
(Shoghi Effendi, Lights of Guidance, p. 469)

The Báb states that His laws are provisional and depend upon the acceptance of the future Manifestation. This is why in the Book of Aqdas Bahá’u’lláh sanctions some of the laws found in the Bayan, modifies others and sets aside many.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 8)

The passages that form part of the Prayer for the Dead comprise the repetition of the greeting “Allah-u-Abhá” (God is the All-Glorious) six times, each followed by nineteen repetitions of one of six specifically revealed verses. These verses are identical with those in the Prayer for the Dead revealed by the Báb in the Bayan. Bahá’u’lláh added a
supplication to precede these passages.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 170)

The severe laws and injunctions revealed by the Báb can be properly appreciated and understood only when interpreted in the light of His own statements regarding the nature, purpose and character of His own Dispensation. As these statements clearly reveal, the Bábí Dispensation was essentially in the nature of a religious and indeed social revolution and its duration had therefore to be short, but full of tragic events, of sweeping and drastic reforms. These drastic measures enforced by the Báb and His followers were taken with the view of undermining the very foundations of Shiah orthodoxy, and thus paving the way for the coming of Bahá’u’lláh. To assert the independence of the new Dispensation, and to prepare also the ground for the approaching Revelation of Bahá’u’lláh the Báb had therefore to reveal very severe laws, even though most of them, were never enforced. But the mere fact that He revealed them was in itself a proof of the independent character of His Dispensation and was sufficient to create such widespread agitation, and excite such opposition on the part of the clergy that led them to cause His eventual martyrdom.
(Shoghi Effendi, Lights of Guidance, p. 469)

The system of inheritance which provides for distribution of the deceased’s estate among seven categories of heirs (children, spouse, father, mother, brothers, sisters, and teachers) is based on the provisions set out by the Báb in the Bayan.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 183)

The weight of the traditional mithqal used in the Middle East is equivalent to 24 nakhuds. However, the mithqal used by the Bahá’ís consists of 19 nakhuds, “in accordance with the specification of the Bayan” (Q and A 23).
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 200-201)

These are the verses that were revealed aforetime, but lo, the Point of the Bayan now calleth out, exclaiming, “O Best-Beloved of the worlds! Reveal Thou in their stead such words as will waft the fragrance of Thy gracious favours over all mankind. We have announced unto everyone that one single word from Thee excelleth all that hath been sent down in the Bayan. Thou, indeed, hast power to do what pleaseth Thee. Deprive not Thy
servants of the overflowing bounties of the ocean of Thy mercy! Thou, in truth, art He Whose grace is infinite.” (Bahá’u’lláh, The Kitáb-i-Aqdas, p. 64)

Today the Bayan is in the stage of seed; at the beginning of the manifestation of ‘Him Whom God shall make manifest’ its ultimate perfection will become apparent.... The Bayan and such as are believers therein yearn more ardently after Him than the yearning of any lover after his beloved.... The Bayan deriveth all its glory from ‘Him Whom God shall make manifest.’ All blessing be upon him who believeth in Him and woe betide him that rejecteth His truth.”
(Shoghi Effendi, The World Order of Bahá’u’lláh, p. 100)

Whatsoever ye understand not in the Bayan, ask it of God, your Lord and the Lord of your forefathers. Should He so desire, He will expound for you that which is revealed therein, and disclose to you the pearls of Divine knowledge and wisdom that lie concealed within the ocean of its words. He, verily, is supreme over all names; no God is there but Him, the Help in Peril, the Self-Subsisting.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 84)