Why Not Whole Salah In One's Own Language
Matters of Ibadah which are transmitted through ijma and tawatur as an initiated Sunnah of Prophet Muhammad (sws) cannot be subjected to ijtihaad. Of course we can try to understand reason behind every Ibadah and every other matter surrounding it. But the way Ibadah is to be done and the concessions to be mindful of are things not subject to our own ijtihaad. So when Sunnah states to recite Quran in Salah, it obviously follows to read Quran in Arabic only, any translation of Quran cannot replace real Quran in Arabic. Same goes for other rituals and utterances made obligatory in Salah through Sunnah. To understand the matter from a Principle stand-point , please see : Discussion 34437 • Reply 44909 Please refer to the following response by Ghamidi Sahab from 1:21:11 to 1:23:42 https://youtu.be/EuvlYdkgehg?t=4871