The following is excerpted from Fatwa of Shaykh Muhammad Ali Ferkous from his website. Full fatwa can be read @ http://ferkous.com/home/?q=en/fatwa-en-592
As for the heresies innovated by Ar-Râfida(3), like the fact of imposing thirst to themselves and showing sadness as well as other innovations, like considering this day a day of sorrow and, on the other hand, An-Nâssiba(4) who show joy and happiness and expend much in this day; neither the former nor the latter have a valid origin on which to rely, but there are only invented hadiths attributed falsely to the Prophet صلَّى الله عليه وسلَّم or weak hadiths that do not reach the degree of validity to be taken as proofs.
Sheikh Al-Islâm Ibn Taymiya رحمه الله demonstrated this by saying:
“Like what was innovated by some people who follow their passions during the day of `Ashura, as making themselves thirsty, showing sadness, gathering and other heresies that are not legislated neither by Allah nor by His Prophet صلَّى الله عليه وسلَّم and none of the Salaf (Predecessors) or one of Ahl-Al-Bayt (The Prophet’s صلَّى الله عليه وسلَّمFamily) or others… this was an affliction to the Muslims – that is to say, the murder of Al-Hussayn رضي الله عنه – and that should be dealt with like other calamities by saying the legal Istirjâ`(5). Yet, some heretics innovated, during this day, acts that contradict what Allah عزَّ وجلَّ ordered to do when a calamity occurs. They added to that calumnies and denigration of the Companions who are innocent of killing Al-Hussayn رضي الله عنه and other things that Allah عزَّ وجلَّ and His Prophet صلَّى الله عليه وسلَّم detest… As for the fact of considering days of calamities as days of bereavement, this does not belong to the Islamic religion but rather to the religion of the pre-Islamic period”,
then Ibn Taymiya رحمه اللهsaid:
“Some people innovated things during this day (`Ashura) on the basis of invented hadiths that have no valid origin like: the merit of taking a ritual bath in this day, to make up with kohl and shaking hands. All these things and others are innovated and hateful, but what is recommended is to fast during this day… apparently, as regards the invention of these hadiths, when chauvinism appeared between An-Nâssiba and Ar-Râfida, the former made the day of `Ashura a day of bereavement, and the latter invented texts that require expending copiously and making of `Ashura a holiday. However, these two ways are false”(6).
If we know that what was prescribed during this day is limited to fasting, it is not allowed to answer the invitation of someone who considers it a day of bereavement, nor someone who considers it a holiday, because it is not allowed to alter the sharia of Allah عزَّ وجلَّ for the sake of someone or rectify and add something to it.
(3) Ar-Râfida: a sect belonging to the large sect of Shiites, they took the oath of allegiance to Zayd Ibn `Ali, and asked him to renounce the two Sheikhs (Abu Bakr and `Umar رضي الله عنهما), so he disagreed with them, then they left and refused him, that is to say: they boycotted him and gave up their oath of allegiance. Among their principles: Al-‘Imâma (The imamship of twelve members of the lineage of the Prophet صلَّى الله عليه وسلَّم), Al-`Isma (The infallibility of the twelve imams), Al-Mahdiyya (They believe in a person of the lineage of the Prophet صلَّى الله عليه وسلَّم whose name is Muhammad Ibn Al-Hassan Al-`Askari who will come back at the end of the world), At-Taqiyya (To show the contrary of what one believes), in addition to insulting the Companions and other principles.
(4) An-Nâssiba: those who detest Ali رضي الله عنه and his companions. See: “Majmû`Al-Fatâwa” (25/301).
(5) Saying: “Inna Lillâh Wa Inna Ilayhi Râji`ûn” (Truly! To Allah we belong and truly, to Him we shall return).
(6) See: “Iqtidhâ’ As-Sirât Al-Mustaqîm” of Ibn Taymiya (2/129-133).