Abu Qatadah (May Allah be pleased with him) reported: The Messenger of Allah (ﷺ) was asked about observing As-Saum (the fast) on the tenth day of Muharram, and he replied, "It is an expiation for the sins of the preceding year."[Muslim].

Abu Qatadah (May Allah be pleased with him) reported: The Messenger of Allah (ﷺ) was asked about observing As-Saum (the fast) on the tenth day of Muharram, and he replied, "It is an expiation for the sins of the preceding year."[Muslim].

وعن أبي قتادة رضي الله عنه أن رسول الله صلى الله عليه وسلم سئل عن صيام يوم عاشوراء فقال‏:‏ ‏ "‏يكفر السنة الماضية‏"‏ ‏(‏‏(‏رواه مسلم‏)‏‏)‏‏.‏