The Prophet ﷺ used to deliver the Khutba while standing and then he would sit, then stand again as you do now-a-days.  

كَانَ النَّبِيُّ ﷺ يَخْطُبُ قَائِمًا ثُمَّ يَقْعُدُ ثُمَّ يَقُومُ كَمَا تَفْعَلُونَ الآنَ  

Ibn 'Umar said that the Messenger of Allah ﷺ used to deliver the sermon on Friday while standing. He would then sit and then stand (for the second sermon) as they (the Muslims) do nowadays.  

كَانَ رَسُولُ اللَّهِ ﷺ يَخْطُبُ يَوْمَ الْجُمُعَةِ قَائِمًا ثُمَّ يَجْلِسُ ثُمَّ يَقُومُ قَالَ كَمَا يَفْعَلُونَ الْيَوْمَ  

[Machine] About the Prophet ﷺ , it is narrated that he used to deliver the sermon standing on the day of Friday, then he would sit, and then he would stand and deliver the sermon.  

عَنِ النَّبِيِّ ﷺ أَنَّهُ كَانَ يَخْطُبُ يَوْمَ الْجُمُعَةِ قَائِمًا ثُمَّ يَقْعُدُ ثُمَّ يَقُومُ فَيَخْطُبُ  

[Machine] The Messenger of Allah ﷺ used to pray on the day of Eid and then deliver a sermon.  

كَانَ رَسُولُ اللهِ ﷺ يُصَلِّي يَوْمَ الْعِيدِ ثُمَّ يَخْطُبُ  

[Machine] The Messenger of Allah ﷺ used to give sermons standing up.  

كَانَ رَسُولُ اللهِ ﷺ يَخْطُبُ قَائِمًا  

[Machine] The Messenger of Allah ﷺ used to give the sermon on Fridays standing, then he would sit down, then he would stand and give the sermon.  

كَانَ رَسُولُ اللهِ ﷺ «يَخْطُبُ يَوْمَ الْجُمُعَةِ قَائِمًا ثُمَّ يَجْلِسُ ثُمَّ يَقُومُ فَيَخْطُبُ»  

[Machine] The Messenger of Allah ﷺ delivered a sermon on Friday standing up.  

«خَطَبَ رَسُولُ اللهِ ﷺ يَوْمَ الْجُمُعَةِ قَائِمًا»  

[Machine] The Messenger of Allah ﷺ used to give a sermon on Fridays, with a pause between them.  

كَانَ رَسُولُ اللهِ ﷺ «يَخْطُبُ يَوْمَ الْجُمُعَةِ مَرَّتَيْنِ بَيْنَهُمَا جَلْسَةٌ»  

[Machine] The Messenger of Allah ﷺ used to deliver speeches standing up.  

«كَانَ رَسُولُ اللهِ ﷺ يَخْطُبُ قَائِمًا»  

"أَن النَّبِىَّ ﷺ كانَ يَخْطُبُ يَوْمَ الْجُمُعَةِ قَائِمًا، ثُمَّ يَقْعُدُ، ثُمَّ يَقُومُ فَيَخْطُبُ".