One day, someone came to the Prophet Muhammad (peace be upon him) and said, "O Messenger of Allah! Give me some advice so that I may take heed." The Prophet replied, "Go and do not become angry." When the person asked for advice again, the Prophet said the same thing. When he asked a third time, the Prophet again advised him to refrain from anger.

This emphatic recommendation indicates that anger is the root of many sins, injustices, oppressions, and crimes. One can prevent many of these afflictions by controlling one's anger. Various expressions and consequences of anger are mentioned in narrations. Among them are:

Anger is like a wild and unruly horse; it is a flame from Satan that burns within the heart. Anger starts with madness and ends with regret. Anger changes how a person speaks, disrupts their reasoning and arguments, and clouds their understanding.

Imam Sadiq (peace be upon him) said, "One who cannot control their anger has no control over their reason and intellect." Therefore, to prevent the key to evil from opening the doors of hell and leading a person to misery, anger must be controlled. Those who cannot overcome their anger and suppress their satanic impulses will ultimately experience regret.