Musannaf Ibn Abi Shayba 27:108

Al-Hasan ibn Musa narrated to us, he said: Hammad ibn Salamah narrated to us, from Farqad al-Sabakhi, from Sa'id ibn Jubayr, from Ibn Abbas, that the Messenger of Allah (may Allah bless him and grant him peace) used to deliver the sermon leaning against a tree trunk. When the pulpit was made, he moved to it, and the trunk moaned. So he went to it and embraced it, and it became quiet. He then said: "If I had not embraced it, it would have moaned until the Day of Resurrection."