73. The Hajj by Vow has prerequisites of: Adolescence, Mind, Freedom, etc. as mentioned in section of Vow in the Jurisprudence texts.
74. If one vowed to visit [the shrine of] Imam Hussain alayhis-salam every year on the day of Arafah, and then he became mostatee' [in a particular year], his vow is waved in that year and he is obliged to perform the Hajj. This is applicable to any vow one may make before being mostatee', and then afterwards becoming mostatee', in cases when he would not be able to meet both requirements, i.e. perform the Hajj and meet the promise of the vow, the vow is waved and he is obliged to perform the Hajj.
75. If he was mostatee' and made a vow that contravenes the Hajj, his vow is not established and he remains obliged to the Hajj.
76. If one vowed to perform Hajjat-al-Islam in a year, and became mostatee' in that year too, or vice versa, i.e. he became mostatee' and then he made that vow, in such a case one Hajj would qualify for him, declaring the niyyah "Hajjat-al-Islam that he vowed".