It is a day in which Allah forgave an entire people.

Tirmidhi relates that the Prophet (Allah bless him and give him peace) said to a man, “If you want to fast a month after Ramadan, then fast Muharram, for it has a day in which Allah forgave an entire people, and He turns to others in repentance in.” [Tirmidhi (841)]

Read more here

« »