Peace be upon you, our Sayed.

You did well and excelled in your investigation about Muhammad ibn al-Hanafiyya; you have excelled, and we have benefited from what your fingertips have generously produced. But a question remains that some repeat in condemning him, namely:
If Muhammad ibn al-Hanafiyya had an excuse for not going out with Imam al-Husayn (a), why did he not send his sons to fight alongside Imam al-Husayn (a)?
In the Name of Allah, the All-beneficent, the All-merciful
And upon you be peace, and the mercy of Allah and His blessings. May Allah be good to you and raise your standing, by the right of Muhammad and the Household of Muhammad.
In answer to the above, we say:
We ought to be aware of an important fact regarding the issue of condemning those who did not go out with Imam al-Husayn (a), namely that not every person who was not with al-Husayn (a) on his journey to Karbala and martyred along with him is condemned for staying behind, since condemnation comes after knowledge of the journey or after being asked.
So unless we know that the matter reached him and that he was asked, we cannot search for a reason, because the occasion for it is absent. There were believers who did not know of the news of Imam al-Husayn’s (a) departure at all, and some of them were in distant lands.
Staying behind from the Imam (a) has two degrees:
The first: Staying behind after being asked.
The second: Staying behind after hearing the cry for help (waʿiya) of the Ahl al-Bayt (a).
It has been narrated that Imam al-Husayn (a) said: (By Allah, no one hears our cry for help and then does not support us, except that he perishes).
The martyrs of al-Taff had a special station with Allah the Exalted, and this station was attained even by some who had been on the side opposed to the Imam, such as al-Hurr ibn Yazid al-Riyahi; among them were some who had been of a religion other than Islam, and among them were some who were not under obligation and from whom [support] was not expected, such as the slaves. This is a great station that they attained and a lofty rank that they ascended, without the slightest doubt; but one who was not among the martyrs is not necessarily judged to have deviated from the Imam (a).
So stations differ even among those who took part with Imam al-Husayn (a) in his general uprising; they are stations, which are particular qualities of persons. When we speak of lofty stations like those reached by the martyrs at al-Taff, we do not, on the other hand, assert the deviation of everyone below them, unless explicit documents reach us showing that they had no excuse; and Allah knows best about their affair.
Discussion of the sons of Muhammad ibn al-Hanafiyya—like discussion of many Muslims about whom history has mentioned nothing in this regard, and of whom it has not been established that Imam al-Husayn (a) asked them to go out with him—is a discussion in which research cannot lead to a clear result. Whoever wants to condemn them must bring evidence for the condemnation, not merely the absence of their names among the martyrs of al-Taff; just as we cannot vouch for them with virtues we do not know of them.
Yes, some historical sources have mentioned that ʿAbd Allah ibn Muhammad ibn al-Hanafiyya was a great scholar, and Ibn Saʿd is reported to have said in his Tabaqat: (Abu Hashim—ʿAbd Allah ibn Muhammad—was trustworthy, and the Shiʿa took him as their master; he was in al-Sham with the Banu Hashim, and he died among them). Accusations of Kaysanism reached him.
He had another son named Jaʿfar, who was killed in the Battle of al-Harra in Medina the Illuminated. As for the rest of his children, it seems they were young, below the age of maturity at the time.
So we know nothing of the stance of these two toward the uprising of Imam al-Husayn (a); as for the door of possibility, it is open in accordance with what befits their standing and the standing of their father, unless the contrary is established.
As for projecting the condition of the sons onto the father, this is a strange thing that has no connection with scholarly research, for (“No bearer shall bear another’s burden” (Qurʾan 6:164; 17:15; 35:18; 39:7))—this if it were established that the sons stayed behind without an excuse, which is not established. So that does not touch the person of Muhammad ibn al-Hanafiyya with any ill.
As for the report of his refusing, and preventing his sons from supporting Imam al-Husayn (a) in Mecca, we mentioned in the article that there is no Shiʿi source for this narration, from which the language of rancor emanates and which does not fit the manner in which Muhammad dealt with his brother Imam al-Husayn (a) in his conversations. It is taken from a Sunni (ʿammi) source, and it cannot be accepted as long as it contradicts the sources we have.
In conclusion, we recall a single narration that has come in the book al-Kafi by Shaykh al-Kulayni, which is among the most eminent of our hadith books. It is a narration from an Infallible, not the report of a historian subservient to the authorities or bearing sectarian rancor; it narrates from Imam al-Hasan ibn ʿAli (a):
(O Muhammad ibn ʿAli, shall I not tell you what I heard from your father about you? He said: Yes. He said: I heard your father (a) say on the day of Basra: Whoever loves to be dutiful to me in this world and the Hereafter, let him be dutiful to Muhammad, my son). Vol. 1, p. 301.
This is a perpetual commendation from the Commander of the Faithful (a); it does not concern worldly matters but concerns dutifulness to the Imam even in the Hereafter, and the path to that, as the Imam stipulated, is dutifulness to his son Muhammad (r). We know that the Ahl al-Bayt (a) do not compromise on the truth and do not flatter at the expense of reality. So whoever wants the guidance of the Ahl al-Bayt (a) should read history according to their foundations and by the light of their lamp.
Sayed Mahmoud Al-Mosawi
And all praise belongs to Allah, Lord of all the worlds.