It was narrated from Ghudaif bin Al-Harith that he asked 'Aishah in which part of the night would the Messenger of Allah (ﷺ) perform Ghusl? She said:"Sometimes he performed Ghusl at the beginning of the night and sometimes he performed Ghusl at the end." I said: "Praise be to Allah Who has made the matter flexible

English translation · Sunan an-Nasa'i