Fasting of Ashurah
Imaam nawawee said (may Allah have mercy on him)
in the explanation of Saheeh Muslim in the chapter: Fasting on the day of Al-‘Ashurah” the consensus of the scholars is upon that the fast of ashurah is Sunnah”
Was the fasting of Ashurah obligatory or was it just Sunnah always?
There are two opinions in this
That it was mustahab (Encouraged) only and this is the opinion of the Jamhoor (Majority of the scholars).
They use as a proof the narration of Mua’awiyah bin Abee Sufiyaan in the Saheeheen (Bukhaari & Muslim) he said ” I heard the Messenger of Allah saying ” Verily this the day of Al-‘Ashurah and Allah has not written upon you it’s fast( i.e. made it waajib) so whoso ever will fast and whoso ever wills leave it” :Bukhaari 2003 Muslim 1129
That it was waajib (obligatory) then it was abrogated and it became mustahab (Encouraged) when fasting ramadaan was made obligatory. this is the opinion of Imaam Ahmed, Hannifa, an opinion with Shafiee and it is it is deemed to be the correct opinion by a group of Muhagigeen (checkers of books) like Ibn Hazam, As-Shookanie and before them Hafith Ibn Hajar and other than them.
They use as proof for this as which follows:
1) The narration of Aisha (may Allah be pleased with her) said ” Quraish use to fast ashurah in the days of Jahiliyyah (Ignorance) and the Messenger use to fast it, when he migrated to Madeenah he fasted it and he commanded it to be fast, but when the month of ramadaan was made obligatory he said ” he who wills can fast and he who wills can leave it” Bukhaari 1893 and Muslim 1125
2) The narration of Abee mosa (may Allah be pleased with him) in the Saheeheen he said ” verily the prophet said ” Fast it you” (i.e. the companions) may Allah be pleased with them all
3) The narration of Salam bin Akwa’a and Al-Rabbe Bint Mua’ad (may Allah be pleased with them both) in the Saheeheen that the prophet of Allah said ” Whoever ate let him complete what is left of his day (i.e. carry on eating) and whoever did not eat let him complete his fast”
As for the Hadeeth of Mua’awiyah bin Abee Sufiyaan (may Allah be pleased with him) ” and Allah has not written it’s fast upon you” It is said by Ibn Qudaamah (may Allah have mercy on him) ” It is held upon(the Hadeeth of Mua’awiyah bin Abee Sufiyaan) the meaning that it is not obligatory upon you now, what helps this is that Mua’awiyah was among the latter Muslim (i.e. to submit to Islaam)
The sheikh holds that the second opinion in the correct one then he says “Allah know best”
Taken for “Fath-ul-A’laam” by Sheikh Mahammed Hizaam Volume 2 Kitab-ul-Siyaam
Translated and compiled by: Abu Rajab Ahmed Sheikhee
Taken from : http://aloloomenglish.net/vb/showthread.php?637-Fasting-of-Ashurah