It is narrated from Sayyiduna Khuzaymah bin Thabit (may Allah be pleased with him) that a Bedouin asked the Prophet (peace and blessings be upon him) about wiping over the leather socks (khuffs), and he (peace and blessings be upon him) said: "For the traveller three days and three nights, and for the resident one day and one night." And had we asked him for more, he (peace and blessings be upon him) would have made it five days.
Hadith Referenceالمعجم الكبير للطبراني / باب الخاء / 3736