The brethren said, “Abba Arsenius said unto one of the brethren, ‘Lead the ascetic life with all the strength that you have, and the hidden labour which is within, and which is performed for God’s sake, shall vanquish your external passions’; to what does he give the name of passions?”

The old man said, “In this case, Abba Arsenius call the labours of the body ‘passions,’ because they constrain those who toil, and make them feel pain, even as Abba Macarius said, “Constrain your soul with pains and labours of every kind in ascetic excellence.” And this is what Abba Arsenius said to that brother, “Labour with all your might in the work of righteousness, and toil with the labours of the mind more than with all the various kinds of work of the body. For the labours of the body only incite and gratify the passions of the body, but the labours of the mind, that is to say, the thought which is in God, and prayer without ceasing, and the suppression of the thought(s) with humility liberate a man from all the passions, and they vanquish devils, and purify the heart, and make perfect love, and make him worthy of the revelations of the spirit.'”

[Abba Arsenius and Abba Macarius, Apophthegmata Patrum]