Posted on 07/17/2012 by __socrates

A double treaty of marriage common amongst the pagan Arabs, viz, the man marrying the sister or daughter of another, and in return giving his sister or daughter in order to avoid paying the usual dower. It is strictly forbidden by the Muslim religion (see Mishkat. book xii. ch. 11), although it is even now practised by the people of Central Asia.

Based on Hughes, Dictionary of Islam