Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrates from Umm Hani (may Allah be pleased with her) that "in the year of the Conquest (of Makkah) the Prophet (peace and blessings be upon him) took a ritual bath (ghusl), wrapped himself in a single garment and prayed eight rak'ahs."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21356