Uthman ibn Affan reported: The Messenger of Allah, peace and blessings be upon him, said, “Whoever performs ablution in an excellent manner, his sins will depart from his body even from under his fingernails.”
Source: Ṣaḥīḥ Muslim 245
Grade: Sahih (authentic) according to Muslim
عَنْ عُثْمَانَ بْنِ عَفَّانَ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مَنْ تَوَضَّأَ فَأَحْسَنَ الْوُضُوءَ خَرَجَتْ خَطَايَاهُ مِنْ جَسَدِهِ حَتَّى تَخْرُجَ مِنْ تَحْتِ أَظْفَارِهِ
245 صحيح مسلم كتاب الطهارة باب خروج الخطايا مع ماء الوضوء
