"Bring me (water for) Wudu'." So I brought him (water for) Wudu', and he performed Wudu' and wiped over his Khuffs. The Shaikh [1] said: "Isma'il (one of the narrators) is Ibn Ja'far bin Abi Kathir Al-Qari. [1] Meaning the author, and it appears that Ibn As-Sunni who heard the text, said this.  

أَنَّ النَّبِيَّ ﷺ كَانَ إِذَا ذَهَبَ الْمَذْهَبَ أَبْعَدَ قَالَ فَذَهَبَ لِحَاجَتِهِ وَهُوَ فِي بَعْضِ أَسْفَارِهِ فَقَالَ ائْتِنِي بِوَضُوءٍ فَأَتَيْتُهُ بِوَضُوءٍ فَتَوَضَّأَ وَمَسَحَ عَلَى الْخُفَّيْنِ قَالَ الشَّيْخُ إِسْمَاعِيلُ هُوَ ابْنُ جَعْفَرِ بْنِ أَبِي كَثِيرٍ الْقَارِئُ  

[Machine] The Prophet ﷺ, when he went to relieve himself, would go far away. Once, he went to relieve himself while he was on one of his journeys, and he said, "Bring me ablution." So, I brought him ablution. He then took out his hands from under his cloak and performed ablution, and wiped over his socks.  

كَانَ رَسُولُ اللهِ ﷺ إِذَا ذَهَبَ الْمَذْهَبَ أَبْعَدَ فَذَهَبَ لِحَاجَةٍ وَهُوَ فِي بَعْضِ أَسْفَارِهِ فَقَالَ «ائْتِنِي بِوَضُوءٍ» فَجِئْتُهُ بِوَضُوءٍ فَأَخْرَجَ يَدَيْهِ مِنْ تَحْتِ الْجُبَّةِ فَتَوَضَّأَ وَمَسَحَ عَلَى الْخُفَّيْنِ  

"عَنِ الْمُغيرةِ قَالَ: كُنَّا مَعَ رَسُولِ الله ﷺ في سَفَرٍ، وَكَانَ رَسُولُ الله ﷺ إِذَا ذَهَبَ لِحَاجَتِهِ أَبعَد، فَذَهَبَ لِبَعْضِ حَاجَتِهِ، فَقَالَ: ائْتنِى بِوضُوءٍ، فَجِئْتهُ بِوضُوء، فَتَوَضَّأَ وَمَسَحَ عَلَى الْخُفَّيْنِ" .