the husband must sponsor a feast after the consummation of the marriage. this is based on the order of the prophet to 'abur-rahman ibn 'auf to do so, and on the hadith narrated by buraida ibn at-haseeb, who said: "when 'ali sought the hand of faatimah (the prophet's daughter) in marraige, he said that the prophet said: "a wedding (and in another version "a bridegroom") must have a feast." the narrator said: "sa'ad said: '(a feast) of a sheep.' someone else said: 'of such and such a quantity of corn." [ahmad and at-tabaraani: its isnaad is acceptable as al-haafiz ibn hajr says in fathul-baaree: 9/188]