The Book of Purification (Kitab Al-Taharah)
Muslim :: Book 2 : Hadith 537
Shuraih b. Hani said: I came to 'A'isha to ask her about wiping over the socks. She said: You better ask ('Ali) son of Abu Talib for he used to travel with Allah's Messenger (may peace be upon him). We asked him and he said: The Messenger of Allah (may peace be upon him) stipulated (the upper limit) of three days and three nights for a traveller and one day and one night for the resident.