Sahih Muslim 1996

وَحَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا أَبُو خَيْثَمَةَ، عَنْ سِمَاكٍ، قَالَ أَنْبَأَنِي جَابِرُ بْنُ، سَمُرَةَ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَخْطُبُ قَائِمًا ثُمَّ يَجْلِسُ ثُمَّ يَقُومُ فَيَخْطُبُ قَائِمًا فَمَنْ نَبَّأَكَ أَنَّهُ كَانَ يَخْطُبُ جَالِسًا فَقَدْ كَذَبَ فَقَدْ وَاللَّهِ صَلَّيْتُ مَعَهُ أَكْثَرَ مِنْ أَلْفَىْ صَلاَةٍ

Jabir b. Samura said that the Messenger of Allah (ﷺ) used to deliver the sermon while standing. He would then sit down and then stand up and address in a standing posture; and whoever informed you that he (the Holy Prophet) delivered the sermon while sitting told a lie. By Allah. I prayed with him more than two thousand times

Reference

Sahih Muslim 1996

In-book

Book 7, Hadith 46

English

Abdul Hamid Siddiqui