It was narrated that ‘Aishah said: “The Messenger of Allah صلی اللہ علیہ وآلہ وسلم used to pray Witr with nine Rak’ahs, then he would pray two Rak’ahs sitting down. When he grew weaker he prayed Witr with seven Rak’ahs, then he prayed two Rak’ahs sitting down.” (Sahih)