Narrated 'Abdullah bin Abi Qais [A man from Al-Basrah]:
"I asked 'Aishah about the Witr of the Messenger of Allah (ﷺ), how would he perform Witr, was it during the first part of the night or the end of it? She said: 'All of that. Sometimes he would perform Witr during the first part of the night, and sometimes he would perform Witr during the end of it.' So I said: 'All praise is due to Allah who made the matter accommodating.' I said: 'How was his recitation, was he quiet with recitations or loud?' She said: 'He would do all of that. Sometimes he would recite quietly and sometimes aloud.' I said: 'All praise is due to Allah who made the matter accommodating. He said: 'I said: 'How would he deal with sexual impurity? Would he perform Ghusl prior to sleeping or would he sleep prior to Ghusl?' She said: 'He would do all of that. Sometimes he would perform Ghusl then sleep, and sometimes he would perform Wudu and then sleep.' I said: 'Allah praise is due to Allah who made the matter accommodating.'"
English reference: Vol. 5, Book 42, Hadith 2924
Arabic reference: Book 45, Hadith 3174