Sayyiduna Jabir bin Samurah (may Allah be pleased with him) said: The Prophet (peace and blessings be upon him) would stand on the pulpit and deliver the sermon, then sit, then stand and deliver the sermon; he (peace and blessings be upon him) used to sit between the two sermons.
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 1990