Professor Ansarian pointed out in one of his lectures about observing the rights of parents and counted as an arduous task for human beings. There is a Hadith from the Holy Prophet (peace be upon him and his progeny) that says: blessed is the child who fulfills and observe the rights of the parents. the narration only talks about the very issue of respecting parents and fulfilling their rights and it doesn’t talk about whether the parents are believers or infidels or whoever.
source : erfan.ir
