In this same Tablet, ‘Abdu’l-Bahá encouraged the believers to refer questions concerning the application of this law to the Universal House of Justice, which has "the authority to legislate". He stressed that "it is this body which will enact laws and legislate upon secondary matters which are not explicit in the Holy Text".
96. should any one of His servants intend to travel, he must fix for his wife a time when he will return home [#67]
If the husband leaves without informing his wife of the date of his return, and no news of him reaches her and all trace of him is lost, Bahá’u’lláh has stated that, should the husband have been aware of the law prescribed in the Kitáb-i-Aqdas, the wife may remarry after waiting a full year. If, however, the husband was unaware of the law, the wife must wait until news of her husband reaches her (Q and A 4).
97. it behoveth her to wait for a period of nine months, after which there is no impediment to her taking another husband [#67]
In the event of the husband’s failure, either to return at the end of the specified period of time or to notify his wife of a delay, the wife must wait nine months, after which she is free to remarry, though it is preferable for her to wait longer (see note 147 for the Bahá’í calendar).
Bahá’u’lláh states that, in such circumstances, should news reach the wife of "her husband’s death or murder", she must also wait nine months, prior to remarrying (Q and A 27). ‘Abdu’l-Bahá, in a Tablet, has further clarified that the nine months’ waiting period following news of the husband’s death applies only if the husband had been away at the time of his death, and not if he dies while at home.