This work addresses the following topics: The historical trajectory of the "Worship in Turkish/Worship in the Mother Tongue" project before and after the Republic, the organizations established under Mustafa Kemal's control and supervision and the individuals who took part in them, the stance of the Presidency of Religious Affairs on the issue of Worship in Turkish/Worship in the Mother Tongue and which Quran translations were used, the contract the Presidency of Religious Affairs made with Mehmed Akif Ersoy to write a Quran translation and the subsequent developments, the contract Elmalılı Muhammed Hamdi Yazır made with the Presidency of Religious Affairs for a Quran interpretation and the difficulties that followed, the interference of the Ministry of National Education during the period when the Presidency of Religious Affairs was set to publish the interpretation and translation and the resulting problems, the topics that were sought to be removed from Elmalılı's interpretation titled "Hak Dini Kur'an Dili" (The True Religion, the Language of the Quran), and the work titled "Worship in Turkish is Permissible" jointly prepared by Şerafettin Yaltkaya and İzmirli İsmail Hakkı, and the scholarly refutation Elmalılı wrote against this work.