Therefore, keep watch over yourself and be deliberate. If you notice that you are becoming irritable and intolerant, lighten your load a little. If you have the desire to look askance at others, to reproach or instruct or make remarks, you are on the wrong road: he who denies himself, has nothing with which to reproach others. If you think you are becoming “disturbed” by people or by external circumstances, you have not understood your work aright: everything that at first glance appears disturbing is really given as an opportunity to practice in tolerance, patience and obedience. The humble man cannot be disturbed, he can only disturb.

Way of the Ascetics: The Ancient Tradition of Discipline and Inner Growth
Tito Colliander