Sayyidah Umm Salamah (may Allah be pleased with her) narrates: The Prophet (peace and blessings be upon him) used to deliver the sermon in the mosque leaning against the trunk of a date-palm. When he had the pulpit made, that trunk began to weep. The Prophet (peace and blessings be upon him) embraced it, and it became calm.
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and its narrators have been declared trustworthy.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 3109