Enchiridion 47

When you have become adjusted to simple living in regard to your bodily wants, do not preen yourself about the accomplishment; and so likewise, if you are a water-drinker, do not on every occasion say that you are a water-drinker. And if ever you want to train to develop physical endurance, do it by yourself and not for outsiders to behold; do not throw your arms around statues, but on occasion, when you are very thirsty, take cold water into your mouth, and then spit it out, without telling anybody.

Epictetus, Enchiridion 47, translated by W. A. Oldfather

When at a small cost you are supplied with every thing for the body, do not be proud of this; nor, if you drink water, say on every occasion, I drink water. But consider first how much more frugal the poor are than we, and how much more enduring of labour. And if you ever wish to exercise yourself in labour and endurance, do it for yourself, and not for others: do not embrace statues. But if you are ever very thirsty, take a draught of cold water, and spit it out, and tell no man.

Epictetus, Enchiridion 47, translated by George Long

When you have adopted the simple life, do not pride yourself upon it, and if you are a water-drinker do not say on every occasion, 'I am a water-drinker.' And if you ever want to train laboriously, keep it to yourself and do not make a show of it. Do not embrace statues. If you are very thirsty take a good draught of cold water, and rinse your mouth and tell no one.

Epictetus, Enchiridion 47, translated by P. E. Matheson