عَنِ ابْنِ عُمَرَ
قَالَ: كَانَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَخْطُبُ خُطْبَتَيْنِ كَانَ يَجْلِسُ إِذَا صَعِدَ الْمِنْبَرَ حَتَّى يَفْرُغَ أُرَاهُ الْمُؤَذِّنَ ثُمَّ يَقُومُ فَيَخْطُبُ ثُمَّ يَجْلِسُ وَلَا يَتَكَلَّمُ ثمَّ يقوم فيخطب
The Prophet (sallallahu alayhi wa sallam) used to deliver two sermons. He would sit down when he ascended the pulpit till he (I think he meant the muadhdhin) was finished. He would then stand up and preach, then sit down and say nothing, then stand up and preach.