Enchiridion 28

If someone handed over your body to any person who met you, you would be vexed; but that you hand over your mind to any person that comes along, so that, if he reviles you, it is disturbed and troubled—are you not ashamed of that?

Epictetus, Enchiridion 28, translated by W. A. Oldfather

If any person was intending to put your body in the power of any man whom you fell in with on the way, you would be vexed: but that you put your understanding in the power of any man whom you meet, so that if he should revile you, it is disturbed and troubled, are you not ashamed at this?

Epictetus, Enchiridion 28, translated by George Long

If any one trusted your body to the first man he met, you would be indignant, but yet you trust your mind to the chance comer, and allow it to be disturbed and confounded if he revile you; are you not ashamed to do so?

Epictetus, Enchiridion 28, translated by P. E. Matheson