Once Messenger of Allah ﷺ went out to answer the call of nature and I followed him with a tumbler containing water, and when he finished, I poured water and he performed ablution and passed wet hands over his Khuffs (socks made from thick fabric or leather). (Using translation from Bukhārī 203)
عَنْ رَسُولِ اللهِ ﷺ أَنَّهُ خَرَجَ لِحَاجَتِهِ فَأَتْبَعَهُ الْمُغِيرَةُ بِإِدَاوَةٍ فِيهَا مَاءٌ «فَصَبَّ عَلَيْهِ حِينَ فَرَغَ مِنْ حَاجَتِهِ فَتَوَضَّأَ وَمَسَحَ عَلَى خُفَّيْهِ»