Diseases of the Heart Prophet Muhammad ﷺ informed us in a very famous narration, commonly quoted with reference to lawful and unlawful, about the important role of the heart. He ﷺ said: “Both lawful and unlawful matters are evident but in between them there are doubtful (suspicious) things and many people have no knowledge about them. So whoever saves himself from these suspicious matters (by staying away from them) saves his religion and his honor. And whoever indulges in these suspicious matters (will eventually) indulge in what is forbidden. This is like (the example of) a shepherd who grazes (his animals) near the Hima (private pasture) of someone else and at any moment he is liable to get in it. (O people!) Beware! Every king has a Hima and the Hima of Allah on the earth is His illegal (forbidden) matters. Beware! There is a piece of flesh in the body, if it is reformed, the whole body becomes good, but if it gets spoilt the whole body gets spoilt; indeed it is the heart.” [Al-Bukhaari]