Al-Ḥakīm al-Tirmidhī explains Quranic concepts in many places in his works. One of these concepts is the heart. He considers the heart as one of the organs of the body, and sometimes he calls it an organ and sometimes it is called a part of body, he places it next to other organs, he talks about its interactions with other organs, and he explains different human behaviors based on the different states of their heart. Sometimes, for such a heart, organs such as eyes, ears, blood vessels, knots, and lust are considered, he explains how Satan finds his way into the heart through his entry into the heart vessels, and he gives other attributes to the heart which are, at least from the dominant view of the commentators of the Qur'an, descriptions of a nature other than the organ of heart. The sum of these descriptions has made it difficult to understand al-Ḥakīm al-Tirmidhī's mental picture of the Quranic concept of heart. In this study, by reviewing and categorizing his scattered explanations, we should reread his understanding of this concept from the heart. The hypothesis of this study is that Al-Ḥakīm al-Tirmidhī attributed immaterial effects such as light, knowledge, wisdom, emotional states and the like to the human physical heart, and explained all these attributes based on his medical knowledge about the human heart as an Iranian Ḥakīm.