The pillow on which the Messenger of Allah ﷺ used to recline was made of leather stuffed with palm fibers.
حدثنا هناد حدثنا عبدة عن هشام بن عروة عن أبيه
كانت وسادة رسول الله ﷺ التي يضطجع عليها من أدم حشوها ليف
Its isnad is sahih. Muslim narrated it in Kitab al-Libas wal-Zinah, "Chapter on Humility in Dress and Making Do with Coarse and Modest Clothing," etc., hadith no. 2082, from the hadith of Abdah bin Sulayman with the same wording. It also has supporting narrations in Bukhari, hadith no. 2468, and in Muslim and others.