What the Qur'an says it treats
Four things named, and one of them is internal.
يَـٰٓأَيُّهَا ٱلنَّاسُ قَدْ جَآءَتْكُم مَّوْعِظَةٌ مِّن رَّبِّكُمْ وَشِفَآءٌ لِّمَا فِى ٱلصُّدُورِ وَهُدًى وَرَحْمَةٌ لِّلْمُؤْمِنِينَ
Yā ayyuha-n-nāsu qad jā'atkum mawʿiẓatun min rabbikum wa shifā'un limā fi-ṣ-ṣudūri wa hudan wa raḥmatun li-l-mu'minīn.
“O mankind, there has come to you instruction from your Lord and healing for what is in the breasts and guidance and mercy for the believers.”
Source
The Qur'an · 10:57
Qur'an
- Qur'anic text in the Uthmani script via Quran.com; translation: Saheeh International