In the Quran, *Ṣadr* represents the spiritual front-line of human consciousness. It is the place where whispers (*Waswās*) enter, where hidden feelings reside, and where Allah grants relief by 'expanding' it (*Sharḥ aṣ-ṣadr*) with guidance, peace, and light.

Associate *Ṣadr* with Surah Ash-Sharh (*Alam nashrah laka ṣadrak* - 'Did We not expand for you your breast?') and Surah An-Nas (*Yuwaswisu fī ṣudūri an-nās*).