The article analyzes the Qur’anic concepts of the structure of human being (descriptive religious anthropology). Qur’anic anthropology includes primarily elements such as «[carnal] soul» ( nafs ), «heart» ( qalb ) and «spirit» ( ruh ). In addition to the «heart» ( qalb ), we can talk about its various aspects, called «breast» ( sadr ), «atrium» or «inner heart» ( fu’ad ), «secret heart» ( sirr ) and the «core [of heart]» (libb). The subject of the present article is the concept of «breast» ( sadr ) in the Qur’an and its development in a sequence of motifs, such as: the breast as a universal concept (1); the correlation between “breast” ( sadr ) and “heart” ( qalb ), including, for example, the motif «heart - stone» (2); «that which is in the breast» (3); «expansion» and «concealment of the breast” (4); hamartiological (5) and soteriological (6) motifs.