What are the reasons the two Imams al-Hasan and al-Husayn (a) were not with their father at the prayer, and is it conceivable that they were asleep?
In the Name of Allah, the All-beneficent, the All-merciful
We have not found that the historical reports mention that the two Imams al-Hasan and al-Husayn (a) were asleep, and this description is not valid with regard to them unless the interest of religion required it; so we should not volunteer the claim that they were asleep.
It is true that they were not in the mosque when the accursed Ibn Muljam struck the Imam, the Commander of the Faithful (a), since the historical reports mention that Imam al-Hasan (a) caught up with Imam ʿAli (a) while he was on his way to the mosque—and some of them mention that he accompanied him up to the door of the mosque—and he said to him: (O father, I want to go with you), but Imam ʿAli (a) ordered him to go back, so he went back.
As for Imam al-Husayn (a), it has come in numerous historical reports that he hurried with his brother al-Hasan to the mosque after their father was struck, after they heard Jibraʾil’s announcement of death in the heavens: (By Allah, the pillars of guidance have collapsed, and by Allah, the stars of heaven have been effaced…).
Some sources sufficed with mentioning the incident of Imam al-Hasan’s (a) return in words like those we have mentioned, but some sources mention that the Commander of the Faithful (a) said to him: (Go back to your bed (firash)). This does not necessarily mean the bed for sleeping; rather, it is also used to mean the wife, or the furnished home that is prepared and suitable, as occurs in the usage of the Noble Qurʾan. In any case, the ultimate intent is that he called him to return to the place of the bedding, which is the home, and not to the state of lying down.
Those sources mention that he gave the reason for this with the words (lest your sleep be troubled). It seems that the intent is: if you see what will be deemed lawful against me—the killing and the blow of the accursed one—that scene will trouble you in your sleep all your life, as happened to Imam Zayn al-ʿAbidin (a).
But this does not mean that the whole wisdom lies in what the Imam mentioned; rather, there may be another wisdom behind the absence of al-Hasan and al-Husayn from the mosque for the prayer, such as its being a protection for them, which is a protection of the Imamate—as in the case of Imam Zayn al-ʿAbidin (a) and his illness, which kept him from taking part in the battle.
The order to Imam al-Hasan (a) to go back may have been for the same reason for which Imam al-Husayn (a) turned back the hosts of jinn who came to support him: so that the pen of divine decree would proceed with that for which the best reward is hoped from Allah the Exalted.
Or for any other reason more important than attending the congregation.
And Allah knows best.