Abu Qatada (Radiyallahu 'anh) relates that
the Holy Nabi (Sall Allahu alaihi wa Aalihi wa Sallim) said,
“For fasting the day of ‘Aashooraa’, ( the 10th of Muharram )
I hope that Allah will accept it as an expiation for
(the sins committed in) the previous year” .
(Muslim).
