Sayyiduna Mu'adh bin Anas (may Allah be pleased with him) narrates from Sayyiduna Abu al-Darda' (may Allah be pleased with him) that he said: I heard the Messenger of Allah (peace and blessings be upon him) say: "Indeed, headache and the heat of fever keep afflicting the believer, even if his sins are (as many) as Mount Uhud, and they do not leave him until not even the weight of a mustard seed of sin remains upon him."
This hadith is not narrated from Sayyiduna Abu al-Darda' (may Allah be pleased with him) except with this chain; Ibn Lahi'ah is alone in narrating it.
Hadith Referenceالمعجم الأوسط / باب الباء / 3119
Hadith Takhrij«أخرجه أحمد فى «مسنده» برقم: 22150، 22142، والطبراني فى «الأوسط» برقم: 634»