Despite the huge bulk of research conducted on translation quality assessment, the literature on the translation of the Holy Quran is in its infancy. Since jurists, commentators, and Quranic interpreters analyze individual Quranic verses as a whole discourse and in relation to other verses and Surahs, it is deemed necessary for translators to follow the same procedure and consider the wholeness of the text in their translation of individual verses. Coherence is among linguistic properties that contribute to the wholeness of the Quran as a unique discourse. A literature review shows that coherence has a direct effect on the quality of translations. Thus, this research intended to investigate the effect of coherence on the translation quality of some famous translations of the Holy Quran from an instructional viewpoint. To this aim, a mixed-methods study was employed in which the effect of coherence on reading comprehension of 12 Ph.D. candidates enrolled in an ESP course was studied. In the qualitative phase, utilizing linguistic markers, samples of coherent translations were extracted from the 30th chapter of the Quran. Then, two reading comprehension tests were developed from the coherent samples and the corpus without coherent markers. In the next step, these tests were administered to participants. The data were analyzed through a t-test. Findings showed that coherent translations enjoy post-posed/pre-posed concessive, sense continuity, backgrounding, explicitation, and addition as coherence markers. Also, quantitative findings showed a significant difference between the tests taken by the participants at two different times (t (11) = 4.204 and p = 0.001) proving the meaningful effect of coherence on translation comprehension.
