Is it true that the Prophet Muhammad (peace be upon him) used to sleep on a pillow made of silk, and is it permissible to sleep on it?

It was not narrated that the Prophet (peace and blessings be upon him) had a silk pillow; rather, his pillow was stuffed with palm fibers. Furthermore, the Prophet (peace and blessings be upon him) forbade men from wearing silk and sitting on it. This prohibition includes sleeping on it, which is a general prohibition for men against using silk in all forms of its use.