Saying 'Salah is better than sleep' in the first or second Adhan

A: The authentic Sunnah (whatever is reported from the Prophet) and the practices of the Muslims, whether the Salaf (righteous predecessors) or their successors, indicate that saying "Salah is better than sleep" should be in the second Fajr Adhan. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.