Hadithcore
Sahih al-Bukhari, 920
sahih

Narrated Ibn `Umar:

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

حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ عُمَرَ الْقَوَارِيرِيُّ، قَالَ حَدَّثَنَا خَالِدُ بْنُ الْحَارِثِ، قَالَ حَدَّثَنَا عُبَيْدُ اللَّهِ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما ـ قَالَ كَانَ النَّبِيُّ صلى الله عليه وسلم يَخْطُبُ قَائِمًا ثُمَّ يَقْعُدُ ثُمَّ يَقُومُ، كَمَا تَفْعَلُونَ الآنَ‏.‏

References2 variants
In-Book Reference
Book 11, Hadith 44
USC-MSA web (English) reference
Vol. 2, Book 13, Hadith 43 (deprecated numbering scheme)
Sharh · explanationclick to expand
The Friday khutbah is one of the greatest symbols of Islam, and attention should be paid to making sure that the message is conveyed and the audience can hear it, so that they may learn from the khatibthat which will bring them closer to Allah (may He be glorified and exalted), and that which will inspire them to seek the reward that is with Allah and make them fear His punishment, by means of effective preaching. In this hadith, Abu Hurayrah (may Allah be pleased with him) speaks of what the Prophet (blessings and peace of Allah be upon him) used to do in the Friday khutbah. It was composed of two khutbahs, which came before the prayer, in which he would exhort the people and teach them about both religious and worldly matters. The way in which these two khutbahs were delivered was that he would stand on the minbar, and separate the two by sitting to rest briefly in between them, facing towards the people. The same is done in the Eid khutbah, except that it is delivered after the prayer. In the beginning, the Prophet (blessings and peace of Allah be upon him) used to stand on the trunk of a palm tree, then he moved to the minbar. .
Related hadiths4
Compare isnād across 4 related chains →