Sunan an-Nasa'i 111
سنن النسائي#111Sahihأَخْبَرَنَا مَحْمُودُ بْنُ غَيْلاَنَ، قَالَ حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا سُفْيَانُ، ح وَأَنْبَأَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا عَبْدُ الرَّحْمَنِ، قَالَ حَدَّثَنَا سُفْيَانُ، - وَاللَّفْظُ لَهُ - عَنْ مَنْصُورٍ، عَنْ هِلاَلِ بْنِ يِسَافٍ، عَنْ أَبِي يَحْيَى، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو، قَالَ رَأَى رَسُولُ اللَّهِ صلى الله عليه وسلم قَوْمًا يَتَوَضَّئُونَ فَرَأَى أَعْقَابَهُمْ تَلُوحُ فَقَالَ " وَيْلٌ لِلأَعْقَابِ مِنَ النَّارِ أَسْبِغُوا الْوُضُوءَ " .
It was narrated that 'Abdullah bin 'Amr said:"The Messenger of Allah (ﷺ) saw some people whose heels were still dry, so he said: 'Woe to the heels from the Fire. Perform Wudu' properly
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 1:111