It is narrated from Sayyiduna Sahl bin Sa'd (may Allah be pleased with him) that the piece of wood that was kept in the maqsurah (enclosure) had been made for the Messenger of Allah (peace and blessings be upon him) in his (peace and blessings be upon him) old age, and he (peace and blessings be upon him) used to lean on it when standing up. When the Messenger of Allah (peace and blessings be upon him) passed away, it was stolen. It was searched for and found in the mosque of Banu Amr bin Awf, and termites had already eaten into it.
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5737