Sunan Ibn Majah, Volume 2, Book 5, Hadith 1228 (DarusSalam) ⓘ

It was narrated that ‘Abdullah bin Shaqiq Al-‘Uqaili said: “I asked ‘Aishah about the prayer of the Messenger of Allah at night. She said: ‘He used to pray for a long time at night standing up, and for a long time at night sitting down. If he prayed standing, he would bow standing, and if he prayed sitting, he would bow sitting.’”

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا مُعَاذُ بْنُ مُعَاذٍ، عَنْ حُمَيْدٍ، عَنْ عَبْدِ اللَّهِ بْنِ شَقِيقٍ الْعُقَيْلِيِّ، قَالَ سَأَلْتُ عَائِشَةَ عَنْ صَلاَةِ، رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ بِاللَّيْلِ فَقَالَتْ كَانَ يُصَلِّي لَيْلاً طَوِيلاً قَائِمًا وَلَيْلاً طَوِيلاً قَاعِدًا فَإِذَا قَرَأَ قَائِمًا رَكَعَ قَائِمًا وَإِذَا قَرَأَ قَاعِدًا رَكَعَ قَاعِدًا ‏.‏