Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) said: "Why should I not fall into error (wahm), when the dirt of one of you is between his fingertips and his nails?"
Al-Bazzar recorded it; its chain contains a narrator, al-Dahhak bin Zayd; Ibn Hibban says: It is not permissible to use him as evidence.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الطهارة / 1227