Simak bin Harb says: I asked Sayyiduna Jabir bin Samurah (may Allah be pleased with him) about the sermon of the Prophet (peace and blessings be upon him), and he said: "He (peace and blessings be upon him) would deliver the sermon standing, then sit down for a while, then stand up again."
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 1873