From Sahih Bukhari (Hadith 918):
Narrated Jabir bin `Abdullah:The Prophet (ﷺ) used to stand by a stem of a date-palm tree (while delivering a sermon). When the pulpit was placed for him we heard that stem crying like a pregnant she-camel till the Prophet (ﷺ) got down from the pulpit and placed his hand over it
Reference: Bukhari 918