Offering a supererogatory Salah before pronouncing the call to start an obligatory one

Q 6: is it permissible for me to offer two Rak`ahs (units of Prayer) before the obligatory Salah (Prayer) if its due time is over?

A: If the Salah is not delayed until just before the end of its due time or the times at which it should be performed, it is permissible to offer the supererogatory Prayers including Al-Sunan Al-Rawatib (supererogatory acts that were stressed and regularly performed by the Prophet). This excludes the person who has an excuse, such as someone who oversleeps at the time of the Fajr (Dawn) Prayer. In this case, they should offer the prior two supererogatory Rak`ahs once they awaken, even if it is after or at sunrise. This is in accordance with what the Prophet (peace be upon him) did when he overslept and missed the Fajr Prayer during some of his travels.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.