Ruling 210

The child of a disbeliever becomes pure by subsequence in two cases:

1. If a disbeliever becomes a Muslim, his child follows him in becoming pure. The same applies if the child’s paternal grandfather, mother, or paternal grandmother becomes a Muslim. However, ruling the child as being pure in this case is conditional upon the child being with the person who has newly become a Muslim and upon the child being under his guardianship; furthermore, a disbeliever who is a closer relative than the person who has newly become a Muslim must not be with the child;
2. If a disbeliever is captured by a Muslim, the disbeliever’s child becomes pure if his father or one of his grandparents is not with the child.

In both cases, in the event that the child is mumayyiz, his becoming pure by subsequence is conditional upon the child not expressing disbelief (kufr).