Is it permissible to interrupt a supererogatory (nafila) prayer if one of the parents calls, and if interruption is obligatory, should the prayer be resumed from where it was interrupted or restarted from the beginning?

Scholars differ on the ruling regarding answering one's parents when they call while one is performing a supererogatory prayer (nafilah). Some hold that it is preferable for him to say "Subhanallah" (glorified be Allah) to them and then shorten the prayer, and that it is disliked for him to interrupt it. Others, however, maintain that it is obligatory to interrupt the prayer if the parents call.

The apparent view is that if completing the supererogatory prayer conflicts with answering one's parents—given that answering parents is more emphatic—then one must interrupt the prayer and answer them. If he wishes to pray afterward, he should not build upon what has passed, but rather start a new prayer.