The offeror must be of the age of legal responsibility (bāligh), sane (ʿāqil), have an intention (qaṣd) to make the offer, and make it of his own volition (ikhtiyār). He must also legally (sharʿan) have disposal over his property. Therefore, the reward of a person who is foolish with finances (safīh) – i.e. someone who spends his wealth in futile ways – is not valid (ṣaḥīḥ).
Similarly, the reward of someone who has been proclaimed bankrupt (mufallas) is not valid with respect to that part of his wealth over which he does not have right of disposal.