According to Sheikh Mohammed al-Arifi, these “temporary marriages for intercourse” (an Islamic legalistic way of permitting prostitution or concubinage) will satisfy the militants’ sexual desires and boost their determination in killing Syrians.
http://frontpagemag.com/2012/dgreenfield/saudi-cleric-promises-paradise-to-14-year-old-girls-who-have-sex-with-syrian-sunni-fighters/