QuestionSome reciters separating between two chapters of the Qur’an by saying “Allahu Akbar” rather than Bismillah, is this permissible? And is there any proof to prove or to disprove this practice? Answer:
The practice you mention is contrary to how the Companions would separate chapters of the Qur’an and contrary to what the people of knowledge do. The furthest one may go in this regard is to say that some reciters considered in recommended to say “Allahu Akbar” after reading every chapter from “Ad-Dhuha” to the end of the Qur’an, but even then, they recite “Bismillah” at the beginning of each chapter.
The practice you refer to is not Sunnah – it is not related from the Prophet (Sallallahu 'Alayhi wa Sallam). What is legislated is to begin every chapter of the Qur’an – separating one chapter from another – with “Bismillah-ir-Rahman-ir-Rahim,” with the exception being ”Bara’a (i.e. At-Taubah)” since there is no “Bismillah” between it and Surah Al-Anfal.
Shaikh Ibn Uthaimin (Rahimahullah)
Reference: Fatawa Islamiyah Volume 7 Page 81