Musnad Ahmad 907:167

Waki' narrated to us, Sufyan narrated to us, from Simak ibn Harb, from Jabir ibn Samurah: "The Prophet, peace and blessings of Allah be upon him, used to deliver the sermon standing, and he would sit between the two sermons, and he would recite verses from the Quran. His sermon was moderate, and his prayer was moderate."