ENOfficial
It was narrated from 'Abdullah bin 'Amr that: The Messenger of Allah (ﷺ) passed by Sa'd when he was performing ablution, and he said: 'What is this extravagance?' He said: 'Can there be any extravagance in ablution?' He said: 'Yes, even if you are on the bank of a flowing river.'"
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُحَمَّدُ بْنُ يَحْيَى، حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا ابْنُ لَهِيعَةَ، عَنْ حُيَىِّ بْنِ عَبْدِ اللَّهِ الْمَعَافِرِيِّ، عَنْ أَبِي عَبْدِ الرَّحْمَنِ الْحُبُلِيِّ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو، أَنَّ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ مَرَّ بِسَعْدٍ وَهُوَ يَتَوَضَّأُ فَقَالَ " مَا هَذَا السَّرَفُ " . فَقَالَ أَفِي الْوُضُوءِ إِسْرَافٌ قَالَ " نَعَمْ وَإِنْ كُنْتَ عَلَى نَهَرٍ جَارٍ " .
sunnah.com