Hadith no. 740 is a repeat. Read it here.
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.
Narrated Abu Said Al-Khudri:
One day the Prophet sat on the pulpit and we sat around him.
So that’s how it was back then. Circles. Halaqaat. One person speaking and others sitting ‘around’ him. And the khateeb (one who is delivering the sermon) would sometimes sit in the middle, to give his legs some rest, or maybe just to be at the eye level of his audience.
Alhamdulillah, we do have halaqaat of `Ilm these days as well. May Allah increase our knowledge and help us acquire it the way the best of people did. Prophet (SAW) did not have all the teaching methods and resources back then. He did not have access to multimedia or even electricity, really. All he and his students had was Imaan and Ikhlaas. Those students of a completely ‘unprofessional’ institute later on changed the face of this Earth. Precisely, those people.
And here’s an interesting video: