Musnad Ahmad 33:8

Yahya ibn Adam narrated to us, Isra'il narrated to us, from Abu Ishaq, from Sa'id ibn Abi Karb, from Jabir ibn Abdullah, who said: "The Messenger of Allah (peace and blessings of Allah be upon him) used to deliver the sermon leaning against a wooden post. When the pulpit was made for him, it moaned like the moaning of a she-camel for its young. He came to it and placed his hand upon it, and it became quiet."