I asked ʿAʿishah ؓ about wiping over the khuff (leather slippers) and she said: Ask ʿAli ؓ . I asked him and he said: Three days and nights - i.e., for the traveller - and one day and night for one who is not travelling (Using translation from Aḥmad 780)
أَنَّ رَسُولَ اللهِ ﷺ قَالَ ثَلَاثَةُ أَيَّامٍ وَلَيَالِيهِنَّ لِلْمُسَافِرِ وَيَوْمٌ وَلَيْلَةٌ لِلْمُقِيمِ