The human heart contains a hidden fire

The human heart has been so made by Love that, like a flint, it contains a hidden fire which is evolved by music and harmony, and renders us beside ourselves with ecstasy. These harmonics are echoes of that higher world of reality which we call the world of spirits...they fan into a flame whatever love is already dormant in the heart.

~ Al-Ghazzali (12th c.)
Al-Ghazzali On Knowing Yourself and God
By Abû Hâmid Muhammad ibn Muhammad al-Ghazâlî