The means aiding one to attain tranquility in the heart
Recitation of the Qur’aan and pondering upon it
It is the cure for every disease, and deprived is the one who does not seek cure from the Book of Allaah. Allaah (The Most High) said: “It is for those who believe, a guide and a healing.” [Soorah Fussilat: Ayah: 44]
And He (Glorified and Exalted Be He) said: ”And We send down from the Qur’an that which is a healing and a mercy to those who believe (in Islamic Monotheism and act on it), and it increases the Zalimun (polytheists and wrong-doers) nothing but loss.” [Soorah Al-Israa: Ayah: 82]
The entire Qur’an is a healing and mercy for the believers. And He (The Most High) said: ”O mankind! There has come to you a good advice from your Lord (i.e. the Qur’an, ordering all that is good and forbidding all that is evil), and a healing for that (disease of ignorance, doubt, hypocrisy and differences, etc.) in your breasts.” [Soorah Yoonus: Ayah: 57]
The Qur’aan is a complete cure for all the diseases of the heart and the body; and it is a cure for all the diseases of this worldly life and the hereafter.
[Source: Inshiraah As-Sadr: page: 163]
And Allaah knows best