The Method of Becoming Mahram for Sister-in-law
Issue No. 2132- If a person wishes for his sister-in-law (his brother’s wife) to become his maḥram, he can contract a temporary marriage with a suckling girl with the permission of her legal guardian and at the same time his sister-in-law should breastfeed her fully. And as an obligatory precaution, the period of the temporary marriage should be long enough to include the time she is able to derive sexual pleasure, and that such a marriage should also be in the interest of the girl.
