It is customary among Muslims to pay tribute to their deceased person forty days after his death. This is because the Holy prophet (pbuh) has said; “The earth mourns the death of a believer for forty mornings”. (Bihar al-Anwaar)
Imam Ja’far Sadiq (pbuh) has said, “The sky wept over Hosein (pbuh) for forty mornings with blood, while the earth wept over him for forty mornings with blackness. The sun wept over him for forty mornings with an eclipse and with redness, whereas the angels wept over him for forty mornings. The Arba’een of Imam Hussein (pbuh) falls on the 20th Safar every year. Shia all over the world will be mourning Imam Hussein (pbuh), his companions and his household members who were brutally massacred in Karbala in the year 61 A.H. by the army of Yazeed bin Mu’awiya bin Abi Sufyan (May the curse of the Almighty be upon them). Shia will also be remembering the atrocities, which were committed against the household of Prophet Muhammad (saww) by the Umayyad rulers.
Amongst the highly recommended actions for this day is to be in Karbala, the grave of Imam Hussein (pbuh) for his Ziyaarah and that of the other Martyrs of Karbala. According to Imam Jafar al-Sadiq (pbuh), one should also recite Ziyaarah-e-Arba’een (Salutations to Imam on the 40th day of his martyrdom). This Ziyaarah can be found in Almanac, page no.238 and also in Mafatih al-Jinaan.
Mourning Hussein (pbuh) is the tradition of all our Aimmah (pbuh) and was started by Imam Ali Bin Hussein (pbuh) after his return to Medina from the prison of Damascus. It is related that after his return to Medina, Imam Ali bin Hussein (pbuh) stayed aloof from the public in order to avoid being involved in their disputes and also to dedicate his time to worshipping Allah (SWT) and mourning his beloved father. He (pbuh) used to weep day and night. One of his slaves said to him, “I fear for you lest you should perish”. He (pbuh) said to him, “I only convey my complaints and my grief to Allah, and I know from Allah what you all do not know. Ya’qoob (Jacob) was a prophet whom Allah caused one of his sons to be separated. He had twelve sons and he knew that his son Yusuf (Joseph) was still alive, yet he wept over him till he lost his eyesight. If you look at my father, my brothers, my uncles, and my friends, how they were slain all around me, tell me how can my grief ever end? Whenever I remember how Fatima’s children were slaughtered, I cannot help crying. And whenever I look at my aunts and sisters, I remember how they were fleeing from one tent to another…” (Karbala & Beyond)