'When we were traveling, Allah's Messenger would order us not to remove our Khuff for three days and nights, except for Janabah, but not for defecating, urinating, and sleep."
Jami` at-Tirmidhi Book 1, Hadith 96
← Previous Hadith "The Prophet was asked about wiping over the Khuff. So he said: "Three (days) for the traveler, and one day for the resident."

Jami` at-Tirmidhi Book 1, Hadith 95 Next Hadith → "The Prophet wiped over the Khuff and its bottom."

Jami` at-Tirmidhi Book 1, Hadith 97