How the mourners commemorated the eve of the eighth of the Muharram?

Karbala commemorate on the seventh day and the eve of the eighth of the sacred month of Muharram the condolences rituals of the young hero of At-Taf; Al-Qassem son of Imam Al-Hassan (peace be upon him) who sacrificed himself for the sake of the true message of his grandfather, the Messenger of Allah (prayers and Allah's peace be upon him and his holy Household), that young man who inherited the courage and boldness in the wars from his father Al-Hassan Al-Mujtaba, his grandfather the Commander of the Faithful and his uncle Abu Abdillah Al-Hussayn (peace be upon them) and all other members of Ahl Al-Bayt (peace be upon them).
The Hussayni processions were carrying candles and henna and playing funeral harmony as condolences for the martyrdom of this brave knight who has left this world with all its pleasures to support the master of Bani Hashem and the Imam of his time Imam Al-Hussayn (peace be upon him), and won the highest levels in Paradise, and glory, pride and love in the hearts of those who love him.
The owners of condolences processions all wear white clothes holding candles, chanting during their march the elegies and lamentations about his heroic martyrdom on Ashura between the hands of his uncle Al-Hussayn (peace be upon him). some of these processions include children in their parade, other bring a young man riding a horse and on foot reciting the famous battle poem of Al-Qassem (peace be upon him):
(إِنْ تُنْكروني فَأَنا نَجْلُ الحَسَنْ *** سِبْطُ النَبِيِّ المُصْطفى والمُؤْتَمَنْ)
(هذا حُـسَيْنٌ كالأَسِـيرِ المُرتَهَنْ *** بَيْنَ أُناسٍ لا سُقُوا صَوْبَ المُـزنْ)
“If you do not know me I am the son of Hassan *** the grandson of the Prophet, the chosen one, the trustworthy
this is Hussayn similar to the one captivated by the mortgagor *** in the midst of the people who may be deprived of rain water.”
And this is one of the theatrical presentation of Al-Qassem (peace be upon him) and a representation of his wedding in heaven.
It is to note that the name of Al-Qassem son of Al-Hassan Al-Mujtaba was mentioned in the Ziyarat of Nahiyah al-Muqaddasa stated by Imam Al-Mahdi (may Allah hasten his holy reappearance): "Peace be upon Al-Qassem son of Imam Al-Hassan, the one hit on his head, deprived of his shield, who called his uncle Al-Hussayn and came to his rescue like an eagle and found his young nephew chafing with his hands and feet [in convulsion]. Then the Imam exclaimed, "It is grievous for your uncle that you call him and he does not respond to you, or respond to you but can't help you, or help you and it is not enough. Away with the people who have killed you. They will be arraigned by your father and grandfather on the Day of Judgement. Truly, this is a day whereon the killers are many and the supporters are few." Therefore O Al-Qassem ibn Al-Hassan, may the Lord join us with you on the Day of Resurrection and make you home our resort; and may He curse your murderer, Umar bin Sa'd bin Nufail al-Azdi and send the culprit to hell and punish him with a painful torment.
Al-Qassem was the youngest son of Imam Al-Hassan (peace be upon him). Al-Qassem was born in 47 A.H., three years before his father was martyred. When Imam Al-Hussayn prepared to leave Madina in the month of Rajab 60 AH. Imam Al-Hussayn agreed to take Al-Qassem and his mother Umm Farwah with him after her request. Al-Qassem, although only 13 years old, had, like his cousins Aun and Muhammad, learnt fencing from Al-Abbas and Ali Akbar (peace be upon them). After Imam Al-Hussayn (peace be upon him) delivered his sermon on the eve of Ashura, Then Al-Qassem (peace be upon him) asked, "Am I too included in the list of the martyrs"? Hearing this Imam was moved and said, "O my dear son! How do you consider death (martyrdom in the way of Allah) to be near you"?
Al-Qassem ibn Al-Hassan (peace be upon both of them) replied, "It is sweeter than honey." Imam said, "Verily, by Allah! May your uncle be your ransom! You are one of them, who shall be martyred along with me after having fallen prey to a severity..."