(Imām Bukhārī narrates): Sa'id bin Abi Maryam narrated to us, he said: Muhammad bin Ja'far narrated to us, he said: Zaid informed me from Iyad bin Abdullah bin Abi Sarh from Abu Sa'id al-Khudri, he relates that

the Messenger of Allāh ﷺ used to go out to the place of Eid prayer on the day of Eid al-Fitr and Eid al-Adha. The first thing he would do was lead the prayer, then he would turn and stand facing the people praying, while the people praying were sitting in their rows. He would preach to them and admonish them and give them commands. So if he wished to send out an army, he would prepare it, or if he wished to command something else, he would command it. Then he would return home. Abu Sa'id said: The people continued to follow this practice, until I went out with Marwan, and he was at that time the governor of Madinah, and it was the day of Eid al-Adha or Eid al-Fitr. When we came to the place of prayer, Kathir bin al-Salt had set up a pulpit. Then Marwan began to climb the steps of the pulpit before leading the prayer. I took hold of his garment and pulled it. He pulled away from me until he climbed onto the pulpit, so he gave the sermon before the prayer. I said: By Allāh, you have changed the practice. He said: O Abu Sa'id, that practice which you know has gone. So I said: By Allāh, what I know is better than what I do not know. Then he said: The fact is, people do not sit for us after the prayer, so I have put the sermon before the prayer