What is the ruling on breastfeeding an adult in a vessel out of necessity or otherwise, and is it permissible for him to enter upon his wet nurse after the fifth suckling if there is no necessity?

The general body of scholars holds that adult suckling does not establish a prohibited degree of relationship (mahramiyyah), and that the hadith of Sahlah bint Suhayl concerning the suckling of Salim was a specific dispensation. Accordingly, adult suckling is not permissible, whether out of necessity or otherwise, and it does not result in the establishment of a prohibited degree of relationship.