Mu'adh bin Hisham said:
My father narrated to me, from Qatadah, from Zurarah bin Awfa, from Sa'd bin Hisham, that Aishah said: 'When the Messenger of Allah (ﷺ) prayed witr with nine rak'ahs, he did not sit until the eighth rak'ah. Then he would praise Allah (SWT) and remember Him and supplicate, then he would get up and he wouldn't say the taslim, then he prayed the ninth, then he sat and remembered Allah (SWT) and supplicated. Then he said a taslim that we could hear. Then he prayed two rak'ahs sitting down. When he grew older and weaker, he prayed witr with seven rak'ahs and did not sit until the sixth. Then he got up and did not say the taslim, and prayed the seventh, then he said the taslim, then he prayed two rak'ahs sitting down.'