Hazrat Zir bin Hubaish (may Allah have mercy on him) narrates that I presented myself before Sayyiduna Safwan bin Assal Muradi (may Allah be pleased with him) and asked him about wiping over leather socks (khuffs). He replied that we used to be with the Messenger of Allah (peace and blessings be upon him). He commanded us that while on a journey, we should not remove our leather socks for three days and nights, except in case of major ritual impurity (ghusl due to janabah); but there is no need to remove them because of defecation, urination, or sleep.