The Prophet ﷺ used to deliver the sermon standing, then he would sit down, then stand again and recite verses and remember Allah. His sermon was moderate in length, and his prayer was moderate in length.
حدثنا علي بن محمد حدثنا وكيع ح و حدثنا محمد بن بشار حدثنا عبد الرحمن بن مهدي قالا حدثنا سفيان عن سماك
كان النبي ﷺ يخطب قائما ثم يجلس ثم يقوم فيقرأ آيات ويذكر الله وكانت خطبته قصدا وصلاته قصدا
Recorded by Muslim (see the previous hadith), and Abu Dawud in the Book of Prayer, in the chapter on a man delivering a sermon while leaning on a bow, (no. 1101), from the hadith of Sufyan Thawri, from the hadith of Simak, with the same wording.