Not graded
Musnad Ahmad 9642
وَبِإِسْنَادِهِ هَذَا يَقُولُ أَحْسِنُوا الْوُضُوءَ فَإِنِّي سَمِعْتُ أَبَا الْقَاسِمِ يَقُولُ وَيْلٌ لِلْأَعْقَابِ مِنْ النَّارِ
This hadith has no English translation yet: the Arabic text, the reference and the grade are shown here.
Reported by Ahmad (No. 9642).