Holding a mourning ceremony for the Master of Martyrs and...
Holding a mourning ceremony for the Master of Martyrs and holding meetings in his memory are all done by those who are loyal to him and who follow him.
There is no doubt that those who follow his path are the believers who recognize him as their Imam; so, one of the marks highlighting their iman, as well as their loyalty to the Master of the Youths of Paradise, the one who was killed as he stood to defend the divine Message, is to be present on the Arba’in anniversary at his sacred grave in order to hold a mourning ceremony for him and remember the tragedies that had befallen him, his companions and (‘a).
To twist the meaning of ziyarat al-Arba’in by saying that it means visiting the gravesites of forty believers is simply indicative of twisted mentalities, an attempt at distortion, one which good taste resents. Moreover, it is without any foundation.
Had the goal been to visit forty believers, the Imam (‘a) would have used the term “ ziyarat Arba’in [mu'minin] .” The original wording indicates that ziyarat al-Arba’in is one of the conditions enumerated in the hadith cited above saying that it is one of the marks of one's iman and an indication of his loyalty to the Twelve Imams (‘a). All the Imams who descended from the Prophet (S) were the gates of salvation, the arks of mercy.
Through them can a believer be distinguished from a non-believer. They all left this world after being killed as they stood to defend the Divine Message, accepting the possibility of their being killed for the stand which they took in obedience to the Command of their Lord, Glory to Him, the One Who sent His wahi to their grandfather, the Prophet (S).
Father of Muhammad, al-Hasan (‘a), son of the Commander of the Faithful, ‘Ali (‘a), has pointed out to this fact saying, “The mission that we undertake is assigned to Twelve Imams (‘a) each one of whom is either to be killed or poisoned.” A mourning ceremony ought to be held in commemoration of the Arba’in of each one of them.
The statement made by Imam Hasan al-’Askari (‘a) does not contain any clue restricting the commemoration of the Arba’in to al-Husayn (‘a) alone, but scholars have understood it to imply emphasis on visiting al-Husayn's gravesite in particular, since the cause defended by the Master of Martyrs (‘a) is the one characterized by enjoining what is right and forbidding what is wrong. This is why it is said that Islam started with Muhammad (S) and it stays alive through al-Husayn (‘a).