Narrated Hafsa, the wife of the Prophet (Allah bless him and give him peace), said:
“Allah’s Messenger (Allah bless him and give him peace) used to perform voluntary ritual prayer sitting down , and he would recite the Sura and pronounce it slowly, so that it would seem to be longer than one that was actually longer than it.”
Narrated Ibn ‘'Umar said (may Allah be well pleased with him and his father):
"I performed two cycles of ritual prayer with Allah’s Messenger (Allah bless him and give him peace) before the noon prayer, and two cycles after it, and two cycles after the sunset prayer in his house, and two cycles after the evening prayer in his house.”
“I asked 'A’isha (may Allah be well pleased with her) about the voluntary ritual prayers of Allah’s Messenger (Allah bless him and give him peace), and she said: ‘He used to spend a long night performing the ritual prayer while standing, and a long night while sitting, so if he recited the Qur’an while standing, he would bow and prostrate from a standing position, and if he recited while sitting, he would bow and prostrate from a sitting position.”