Abu Qatadah (May Allah be pleased with him) reported: The Messenger of Allah (PBUH) 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]. Ibn `Abbas (May Allah be pleased with them) reported: The Messenger of Allah (PBUH) said, "If I remain alive till the next year, I shall also observe fast on the ninth of Muharram.'' [Muslim]. Commentary: Some people think these words stand to mean that `he will observe Saum on the 9th of Muharram only. But this interpretation does not agree with other Ahadith. In order to oppose the Jews, he (PBUH) resolved to observe one more Saum (9th of Muharram) with that of 10th of Muharram and ordained it for the Muslims. Please forward this Hadith to your relatives & friends and may Allah SWT reward you. Subscribe and receive Hadith via email Visit >> http://hadith-islam.blogspot.com for subscription.
