It is narrated from Ibn Abbas (may Allah be pleased with them both) that when the Prophet (ﷺ) passed away, he had nine wives in his marriage, and he had assigned turns for eight of them.
Hadith Referenceمسند الإمام الشافعي / كتاب النكاح / 1109
Hadith Takhrijاخرجه البخاري، النكاح، باب كثرة النساء (5067) ومسلم ، الرضاع ، باب جواز هبتها نوبتها لضرتها (1465)۔