Sentence:  Since remarriage is not permitted after three divorces, they arrange <WSD>Halala</WSD> with some one, that is, on the condition that he divorces her, the next day after marriage. 
Meaning of the word marked with <WSD> tags:  A wedlease (temporary marriage) to a stranger undertaken prior to remarriage to an ex, that is to make the remarriage halal, or the woman halala (f) to marry.