Amirul-Mu'minin (a) said...
Amirul-Mu'minin (a) said: “He who is not saved by steadfastness will surely be killed by impatience[^4].” Categories of Patience Steadfastness against Misfortunes and Calamities This category of patience is the greatest because it implies self-dignity, wide-mindedness, unruffledness, and progression. Man is naturally the subject of misfortunes that befall him unwillingly while he has no ability to stop them.
The best thing that such a man may practice in such states is to armor himself with steadfastness without which man will surely collapse and become a palatable bite of grieves: “Give glad news to the people who have patience and in difficulty say, "We are the servants of Allah and to Him we shall all return." It is they who will receive blessings and mercy from Allah and who follow the right guidance.
(2:155-7)” Amirul-Mu'minin (a) said: “If you practice patience, the destined calamity will befall you while you are rewarded. But if you lose your temper, the destined calamity will befall you while you are sinned[^5].” It is worth mentioning that patience that is described as nice stands for the steadfastness against the inescapable calamities, such as loss of a dear person, usurpation of the wealth, or persecution of the enemy.
Submission to calamities, while the ability to protect oneself against them is available, is a sort of foolhardiness that is denied by Islam. The thing that divests of the virtue of patience is the excessive intolerance, such excessive complaint and grumbling. To give vent to the mental pains by means of moderate weeping and to complain about the sufferance of a disease are among the necessities of the vital emotions.
The Prophet (S) said when his son Ibrahim died: “The eyes shed tears and the heart grieves, but we will say nothing that may displease the Lord.” Within the folds of history, there are many stories carrying glorious examples from the past generations who practiced patience remarkably: It is narrated that Khosrow the Persian king, once, was angry with Bozorgmehr; therefore, he detained him in a gloomy house and ordered to enchain him with iron.
Several days later, the king sent some people to investigate his state. As they visited him in that gloomy house, they found him tranquil and cheerful. They were astonished; therefore, they wondered: “How can you enjoy such peace of mind while you are in such miserable state?” He answered: “In fact, I have made, mixed, and used six humors that helped me keep such manner.