It was narrated from Abu Bakr bin Hafs:"I heard Abu Salamah say: 'I entered upon 'Aishah and her foster-brother was with her. He asked her about the Ghusl of the Prophet (ﷺ). She called for a vessel in which was a Sa' of water, then she concealed herself and performed Ghusl and poured water over her head three times

English translation · Sunan an-Nasa'i