It was narrated that when the battle of Karbala began between the forces of Imam Hussain (as) and the Umayyads, and all of the companions of the Imam (as) were killed. The next group that fought was the children of Imam Hassan (as). The first person among them to ask permission to fight was Qassim (as). He went to Imam Hussain (as) and asked: “Grant me permission O’ Uncle to fight those disbelievers“.
The Imam (as) didn’t give him permission, replying: “You are my nephew, and I want you to stay so that I can remain happy with your presence”. Qassim returned to his room depressed and upset, as the Imam granted permission to his brothers but not him. Qassim then remembered that his father had tied a knot on his right shoulder and instructed him not to open that knot unless he was feeling depressed and upset and that if he were to open it, he must do whatever written inside.
Qassim thought to himself: “All these years, I haven’t felt upset or depressed as today“.
So he opened the knot and found a letter inside which read: “O’ My Son Qassim. If you find yourself in Karbala, and see your uncle surrounded by the enemies, then don’t leave jihad and fight the enemies of God and His Prophet. Sacrifice your soul for him, and if he doesn’t grant you permission, then keep asking him so that you may attain eternal happiness in the hereafter“.
Qassim then stood up and went to Imam Hussain and showed him what was written. When Imam Hussain read it, he wept and wailed. He said: “O’ Qassim, this is the will of your father to you, and I also have a will from him that involves you and I must fulfil it“. He then took the hand of Qassim and entered the tent with him. He also took Aun and Abbas. He asked the mother of Qassim if he had any new clothes, but she replied no.
He then instructed his sister Zainab to bring a storage chest, he opened it and took out the turban of Imam Hassan and wrapped it around the head of Qassim. He then took his daughter and read the marriage contract between them, and put her hand on Qassim’s hand and left them alone in the room. He looked at his wife and cried until he heard the enemies call out: “Is there any fighter to combat us?”
He then let go of her hand and got ready to fight them, but then she held onto his clothes and didn’t let him leave, asking: “What is in your head? What are you trying to do?!” He replied: “I am heading towards the battlefield as they are challenging a fighter among us, and defending my uncle is what I shall do until I die”. But she still didn’t let him leave, he then said: “Let me go, Allah has delayed our wedding till the hereafter”.
She was heartbroken; she cried and wailed and said: “How will I know you in the hereafter?” He then tore a part of his shirt and gave it to her, and told her that’s how she’d know him. The entire camp began to weep by that scene. When Imam Hussain (as) saw that Qassim was ready to go to battle, he said: “My Son, you are walking towards your own death”.
Qassim replied: “My Uncle, how do you want me to react when you are alone among the enemies with no supporter nor defender? May my soul be sacrificed for your soul”. Then Imam Hussain (as) helped him get ready and Qassim advanced to the battlefield.
(Reference: Madinat al-Ma’ajiz, volume 3, page 366).
The hadith is mursal
Hadith being mursal doesn’t mean it’s inauthentic. We have many fiqh rules that were established referencing mursal hadiths, and we narrate many hadiths that are mursal, a lot of which have been authenticated by our scholars, such as Sheikh Fathullah al-Isfahani who authenticated the hadith where Sayeda Zainab (sa) hit her head on the pole of the saddle.
The marriage of Qassim (as) hasn’t been mentioned since the classical scholars until very recently.
Just because the classical scholars didn’t list it, doesn’t mean it’s not there. Allamah al-Majlisi mentioned a lot of hadiths that their original sources are not present at current times. Also, Sheikh al-Noori wrote Mustadrak al-Wasail to add the hadiths that were missed by Sheikh al-Hurr al-Ameili in Wasail al-Shia. So it is quite possible that hadith was missed, or its original source was lost as time went by.
The name of Imam Hussain’s daughter hasn’t been mentioned, and he had only three daughters in total.
Generally, the sons and daughters of the infallibles had a lot of debate among scholars. If you go back to any historical book that lists the children of the infallibles, many have differing opinions. For example, a lot have mentioned that a daughter of Imam Hussain (as) passed away in Lebanon, but some don’t even mention her as among the daughters of Imam Hussain (as). Furthermore, the dates of birth and deaths of the infallibles themselves have disagreements among scholars.
To conclude: There is no doubt that the marriage did occur. Some say Qassim was young and wasn’t old enough for marriage – that argument is invalid as the children of Banu Hashem develop more quickly than the rest of the children (as the hadiths indicate). Furthermore, the hadith mentions a marriage contract, not a wedding. And a marriage contract being done while young is very recommended.
Also, Qassim was heading towards death and getting married is the Sunnah of the Prophet, so it’s quite possible that Imam Hussain (as) wanted to get his nephew married before death took him just so he fulfils the Sunnah of his grandfather. Also, the marriage of Qassim is a message to the youth to get married as early and young as possible as it can get a lot of social problems solved.
It is also noteworthy to mention that many scholars believed the marriage occurred, going so far that some even wrote books proving this fact, such as the book titled Asrar al-Shahadat by al-Fadhil al-Darbandi.