The World Federation One Stop Fiqh

Ruling 105

If the father, mother, paternal grandfather, and paternal grandmother of a child who is not of the age of legal responsibility (bāligh) are non-kitābī disbelievers, that child is also impure based on obligatory precaution unless he is mumayyiz and professes Islam, in which case he is pure. If he turns away from his father and mother and inclines towards Muslims, or, if he is in the process of researching and investigating, then ruling him as being impure is problematic [and therefore, based on obligatory precaution, the requisite precautionary action must be taken].13 If either his father, mother, paternal grandfather, or paternal grandmother is a Muslim, then as per the details that will be mentioned in Ruling 210, the child is pure.

13 See Tawḍīḥ al‑Masāʾil‑i Jāmiʿ, vol. 1, p. 69, Ruling 122.