صَحِيحُ مُسْلِمٍ
Sahih Muslim 732 b
The Book of Prayer - Travellers
It is permissible to offer voluntary prayers standing or sitting, and to stand and sit in the same rak`ah
وَحَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُعَاذٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا كَهْمَسٌ، عَنْ عَبْدِ اللَّهِ بْنِ شَقِيقٍ، قَالَ قُلْتُ لِعَائِشَةَ . فَذَكَرَ عَنِ النَّبِيِّ صلى الله عليه وسلم بِمِثْلِهِ .
'Abdullah b. Shaqiq reported: I said to 'A'isha and she made a mention of that (recorded above) about the Messenger of Allah (ﷺ).
Sahih Muslim, 732 bSahihصحيح