I asked Imam (as) about a Christian man who died, leaving behind a Muslim nephew (son of his brother) and a Muslim niece (daughter of his sister), while his own children and wife were Christians. Imam (as) said: "I see that the Muslim nephew should be given two-thirds of what he left behind, and the Muslim niece should be given one-third of what he left behind, provided he does not have young children. However, if he has young children, then the two heirs must provide for the children from what they inherited from their father until the children reach maturity." It was asked: "How should they provide for the children?" Imam (as) replied: "The heir of the two-thirds share must cover two-thirds of the expenses, and the heir of the one-third share must cover one-third of the expenses. Once the children mature, the heirs are no longer responsible for their expenses." It was then asked: "What if his children embrace Islam while they are still young?" Imam (as) said: "In that case, what their father left behind should be handed over to the Imam until they reach maturity. If they remain steadfast in Islam upon reaching maturity, the Imam will give them their inheritance. But if they do not remain in Islam upon maturity, the Imam will return the inheritance to the Muslim nephew and niece, giving the nephew two-thirds of what was left and the niece one-third."