(16) باب جَوَازِ النَّافِلَةِ قَائِمًا وَقَاعِدًا وَفِعْلِ بَعْضِ الرَّكْعَةِ قَائِمًا وَبَعْضِهَا قَاعِدًا
'A'isha reported:
When the Messenger of Allah (ﷺ) grew bulky and heavy he would observe (most of his Nafl) prayers sitting. (ID)
Reference (ID): Sahih Muslim 732 d (ID)
In-book reference (ID): Book 6, Hadith 141 (ID)
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 1596 (ID)