The Kitáb-i-Aqdas - The Most Holy Book
Index term: laws, under Islám
n6.
We have relieved you of a greater number
The requirements for obligatory prayer called for in the Bábí and Islamic Dispensations were more demanding than those for the performance of the Obligatory Prayer consisting of nine rak'ahs that was prescribed in the Kitáb-i-Aqdas (see note 4).
In the Bayán, the Báb prescribed an Obligatory Prayer consisting of nineteen rak'ahs which was to be performed once in a twenty-four-hour period -- from noon of one day to noon of the next.
The Muslim prayer is recited five times a day, namely, in the early morning, at midday, in the afternoon and evening, and at night. While the number of rak'ahs varies according to the time of recitation, a total of seventeen rak'ahs are offered in the course of a day.
n15.
God hath granted you leave to prostrate yourselves on any surface that is clean, for We have removed in this regard the limitation that had been laid down in the Book
The requirements of prayer in previous Dispensations have often included prostration. In the Arabic Bayán the Báb called upon the believers to lay their foreheads on surfaces of crystal when prostrating. Similarly, in Islám, 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".
n18.
We have absolved you from the requirement of performing the Prayer of the Signs.
The Prayer of the Signs is a special form of Muslim obligatory prayer that was ordained to be said in times of natural events, like earthquakes, eclipses, and other such phenomena, which may cause fear and are taken to be signs or acts of God. The requirement of performing this prayer has been annulled. In its place a Bahá'í may say, "Dominion is God's, the Lord of the seen and the unseen, the Lord of creation," but this is not obligatory (Q&A 52).
n89.
Beware that ye take not unto yourselves more wives than two. Whoso contenteth himself with a single partner from among the maidservants of God, both he and she shall live in tranquillity.
While the text of the Kitáb-i-Aqdas appears to permit bigamy, Bahá'u'lláh counsels that tranquillity and contentment derive from monogamy. In another Tablet, He underlines the importance of the individual's acting in such a way as to "bring comfort to himself and to his partner". 'Abdu'l-Bahá, the authorized Interpreter of the Bahá'í Writings, states that in the text of the Aqdas monogamy is in effect enjoined. He elaborates this theme in a number of Tablets, including the following:

Know thou that polygamy is not permitted under the law of God, for contentment with one wife hath been clearly stipulated. Taking a second wife is made dependent upon equity and justice being upheld between the two wives, under all conditions. However, observance of justice and equity towards two wives is utterly impossible. The fact that bigamy has been made dependent upon an impossible condition is clear proof of its absolute prohibition. Therefore it is not permissible for a man to have more than one wife.

Polygamy is a very ancient practice among the majority of humanity. The introduction of monogamy has been only gradually accomplished by the Manifestations of God. Jesus, for example, did not prohibit polygamy, but abolished divorce except in the case of fornication; Muhammad limited the number of wives to four, but making plurality of wives contingent on justice, and reintroducing permission for divorce; Bahá'u'lláh, Who was revealing His Teachings in the milieu of a Muslim society, introduced the question of monogamy gradually in accordance with the principles of wisdom and the progressive unfoldment of His purpose. The fact that He left His followers with an infallible Interpreter of His Writings enabled Him to outwardly permit two wives in the Kitáb-i-Aqdas but uphold a condition that enabled 'Abdu'l-Bahá to elucidate later that the intention of the law was to enforce monogamy.
n101.
The Lord hath prohibited . . . the practice to which ye formerly had recourse when thrice ye had divorced a woman.
This relates to a law of Islám set out in the Qur'án which decreed that under certain conditions a man could not remarry his divorced wife unless she had married and been divorced by another man. Bahá'u'lláh affirms that this is the practice which has been prohibited in the Kitáb-i-Aqdas (Q&A 31).
n161.
payment of Zakát
Zakát is referred to in the Qur'án as a regular charity binding upon Muslims. In due course the concept evolved into a form of alms-tax which imposed the obligation to give a fixed portion of certain categories of income, beyond specified limits, for the relief of the poor, for various charitable purposes, and to aid the Faith of God. The limit of exemption varied for different commodities, as did the percentage payable on the portion assessable.
Bahá'u'lláh states that the Bahá'í law of Zakát follows "what hath been revealed in the Qur'án" (Q&A 107). Since such issues as the limits for exemption, the categories of income concerned, the frequency of payments, and the scale of rates for the various categories of Zakát are not mentioned in the Qur'án, these matters will have to be set forth in the future by the Universal House of Justice. Shoghi Effendi has indicated that pending such legislation the believers should, according to their means and possibilities, make regular contributions to the Bahá'í Fund.