Rayyan bin Shabeeb (the maternal uncle of Mo’tasim), who says that I went to meet Imam Ali ar Ridha’ (a.s.) on the first day of the month of Muharram. Imam Ridha’ (a.s.) asked me,
“O son of Shabeeb! Are you in the state of fasting today”?
I replied in the negative. Imam continued,
“This is the day when Prophet Zakariyyah (a.s.) prayed to his Lord thus:
“Lord grant me from unto Thee a good offspring, Verily Thou art the Hearer of Prayers” (Surah al-Ali Imran, 3:38).
Then Allah accepted his Prayers and commanded His Angels to go and give him glad tidings regarding the birth of his son Prophet Yahya (a.s.). The Angels came and called out to him while he was engaged in Prayers in the niche. Hence the one who fasts on this day and asks for his desires from Allah, his Prayer will be answered as was of Zakariyah.”
Then Imam (a.s.) said,
“O son of Shabeeb! Muharram is such a month that the Arabs of the age of ignorance (pre-Islamic) too respected its sanctity and forbade oppression and blood-shed in it. But these people (the Umayyads) did not honor the sanctity of this month nor of their Prophet. In this month they killed the son of the Prophet and imprisoned the women-folk after looting and plundering their belongings, verily Allah will never ever forgive this crime of theirs.”
“O son of Shabeeb! If you wish to mourn and lament over anyone, do so upon Husayn bin Ali bin Abi Talib (a.s.) for he was beheaded like a lamb. Eighteen persons from among his family, who were unparalleled in the earth, were also killed along with him. The heavens and the earth lamented the death of Husayn (a.s.). Four thousand Angels descended from the heavens to aid him, but when they reached there they saw that he had already been martyred. Thus, now they all remain near his blessed grave with disheveled hair covered with dust until the rising of the Qaem (Imam al Mahdi). Then they will all aid him and their slogan will be: Vengeance for the blood of Husayn.”
“O son of Shabeeb! My father (Imam Moosa al Kazim) has related from his father (Imam Ja’far as Sadiq), who has related from his grandfather (Imam Ali Zainul Abedeen), that when my grandfather Imam Husayn (a.s.) was martyred, the sky rained blood and red sand.”
“O son of Shabeeb! If you weep over the afflictions of Husayn (a.s.) such that tears flow from your eyes and fall upon your cheeks, Allah will forgive all your sins whether big or small and less or large in number.”
“O son of Shabeeb! If you desire to meet Allah the Glorified in a state purified of all sins, then go for the pilgrimage to the grave of Imam Husayn (a.s.).”
“O son of Shabeeb! If you desire that you may abide in the palaces of Paradise in the company of the Holy Prophet (S) and his Progeny, then invoke Allah’s curse upon the murderers of Imam Husayn (a.s.).”
“O son of Shabeeb! If you desire to earn the reward of those who were martyred along with Imam Husayn (a.s.), then whenever you remember him, say: I wish I had been with them, then I too would have attained the Great Triumph.”
“O son of Shabeeb! If you desire to reside in the exalted status of Paradise along with us, then bemoan our sorrows and sufferings and rejoice in our happiness and remain attached to our love. For even if a person is attached to a stone in this world, Allah shall make him arise with it on the day of Qiyamah.”
Reference : Nafasul Mahmoom – Shaikh abbas Qummi (r.a.)