Ibn ‘Umar said that the Prophet used to deliver two sermons. He would sit down when he ascended the pulpit till he (I think he meant the mu’adhdhin) was finished. He would then stand up and preach, then sit down and say nothing, then stand up and preach.
‘Abdallah b. Mas'ud said, “When the Prophet sat down on the pulpit we faced him.”
Tirmidhi transmitted it, and said this was a tradition he knew only among the traditions of Muhammad b. al-Fadl who was weak and whose traditions were not accepted.
Jabir reported God’s Messenger as saying in the course of a sermon, “When one of you comes on Friday while the imam is preaching, he should pray two rak'as and make them short.”