Zirr bin Hubaish (may Allah have mercy on him) says: I came to Safwan bin Assal Muradi (may Allah have mercy on him), and he informed me: When we were on a journey, the Messenger of Allah (peace and blessings of Allah be upon him) used to command us not to remove our leather socks for three days and nights except in case of major impurity (janabah), and not to remove them due to relieving oneself or sleeping.