(27) باب الْخُطْبَةِ قَائِمًا
Narrated Ibn `Umar:
The Prophet (p.b.u.h) used to deliver the Khutba while standing and then he would sit, then stand again as you do now-a-days. (ES)
Reference (ES): Sahih al-Bukhari 920 (ES)
In-book reference (ES): Book 11, Hadith 44 (ES)
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 2, Book 13, Hadith 43 (ES)