Only a few "are consistently presented as key figures in the hadith accounts of contexts of specific revelations ('occasions of revelation', Asbab al-nuzul)". Stowasser states: "The Quranic legislation directed at the Prophet's wives, then, is entirely of Medinan provence and belongs into the last six or seven years of the Prophet's life." Sura 33:50 outlines the lawful "categories of females" that are able to marry the Prophet: "wives with whom the Prophet contracted marriage involving a dower; female prisoners of war (slaves) who fell to him as part of his share of spoils; both paternal and also maternal cousins who had migrated with him to Medina; and "a believing woman, if she gives herself to the Prophet and also wishes to marry her(Al-Quran 33:50)."