"I sat with the Prophet ﷺ and I did not see him deliver the khutbah except standing, and he sat, then he stood up and delivered the second khutbah." (Using translation from Nasāʾī 1415)  

جَالَسْتُ النَّبِيَّ ﷺ فَمَا رَأَيْتُهُ يَخْطُبُ إِلَّا قَائِمًا ثُمَّ يَجْلِسُ ثُمَّ يَقُومُ فَيَخْطُبُ الْخُطْبَةَ الْآخِرَةَ