Temporary Marriage (sigheh)
A man (married or not), and an unmarried woman (virgin, divorced, or widowed) can enter a temporary marriage contract (sigheh or nekah-e monghate'e) in which both parties agree on the period of the relationship and the amount of compensation to be paid to the woman. This arrangement requires no witnesses, and no registration is needed. This form of temporary marriage, according to its proponents, is a measure for curbing free sex and controlling prostitution.
A man can have as many sigheh wives as he can afford, but the woman can be involved in no more than one such temporary relationship at any given time and cannot enter another contract before a waiting period (edda) of three months or two menstrual cycles elapse. This obligatory waiting period also applies to divorced women in permanent marriage and is intended to determine paternity in case the woman becomes pregnant (Haeri 1989). Sigheh has been very unpopular, particularly among the educated middle-class families and among women who tend to associate it with legalized prostitution. It is known to be practiced mainly by widowed or divorced women and is believed to be more common in theological seminaries and among the clergy (Haeri 1989).
Marriage and Family EncyclopediaMarriage: Cultural AspectsIran - Marriage, Endogamy And Polygamy, Arranged Marriages, Temporary Marriage (sigheh), The Family, Premarital Sex And Extramarital Relationships