A: This matter has been explained in reply to question 8 regarding divine justice. For further details please refer to what Allamah Majlisi (r.a.) says in his Haqqul Yaqeen. According to him summarily, it must be believed that there are proofs and evidences to show that in the holy verses and narrations that the Almighty Allah is always just and He is never unjust or wrong to anyone and therefore He will never punish those who are minor or insane or those before whom arguments are not completed or whose intellects cannot distinguish between right and wrong. He will make them live in Araaf, which is between Paradise and Hell, or He will place them at a lower level in Paradise or make them servants of the folks of Paradise.
In an authentic tradition, Kulaini has quoted from Zurarah that he asked Imam Sadiq (a.s.): What will happen to children who die before maturity? He replied that the query was put to the Holy Prophet (s.a.w.s.) and he replied that God knows better, which means that the matter should be left to Him and no more inquiry is advisable in this regard as God will deal with them as demanded by His justice or grace.
It should also be known that if they are made to serve the people of Paradise, such service will not be hard; but they will get pleasure from it just as angels enjoy their duties. It should be clear that whatever was mentioned about Mustazafeen was about other than the children of believers and apparently it does have any contradiction if in the hereafter they join their parents in Paradise and add to their happiness.
It is also mentioned in Al-Kafi, Faqeeh and Tawhid Sadooq that Imam Sadiq (a.s.) said: Though children of the faithful were unable to do any good themselves, God wi1l make them join their parents and please them in Paradise.
Sayyid Abdul Husayn Dastghaib