Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
tabarani:8115ʿAbdān b. Aḥmad al-Ahwāzī > Zayd b. al-Ḥarīsh > Maymūn b. Zayd > Layth > ʿAbd al-Raḥman b. Sābiṭ > Abū Umāmah

[Machine] About the Prophet ﷺ , he saw a man performing ablution for prayer but he left a small spot of his nails untouched by water. So the Messenger of Allah ﷺ commanded him to repeat his ablution and then he said, "Woe to the heels from the Hellfire."  

الطبراني:٨١١٥حَدَّثَنَا عَبْدَانُ بْنُ أَحْمَدَ الْأَهْوَازِيُّ ثنا زَيْدُ بْنُ الْحَرِيشِ ثنا مَيْمُونُ بْنُ زَيْدٍ عَنْ لَيْثٍ عَنْ عَبْدِ الرَّحْمَنِ بْنِ سَابِطٍ عَنْ أَبِي أُمَامَةَ

عَنِ النَّبِيِّ ﷺ أَنَّهُ رَأَى رَجُلًا تَوَضَّأَ لِلصَّلَاةِ وَقَدْ تَرَكَ مَوْضِعَ ظُفْرٍ مِنَ الْوُضُوءِ فَأَمَرَهُ رَسُولُ اللهِ ﷺ أَنْ يُسْبِغَ الْوُضُوءَ ثُمَّ قَالَ «وَيْلٌ لِلْعَرَاقِيبِ مِنَ النَّارِ»