The Messenger of Allah wiped over his leather socks and his head cover (i.e., over the Imamah). (Using translation from Ibn Mājah 561)

قَالَ رَسُولُ اللهِ ﷺ امْسَحُوا عَلَى الْخُفَّيْنِ وَالْخِمَارِ