The bedding of the Messenger of Allah ﷺ on which he slept was made of leather stuffed with palm fibers.
إنما كان فراش رسول الله ﷺ الذي ينام عليه، أدما حشوه ليف.
Bukhari narrated it in the Book of Raqaiq (6456), and Muslim narrated it in the Book of Clothing and Adornment (38:2082), both through Hisham bin Urwa, from his father, from Ayesha, who said, so-and-so mentioned it. It also came with the wording, "the resting place of the Messenger of Allah ﷺ" instead of "the bedding of the Messenger of Allah ﷺ"