From Rohan Healey's Greeks to Geeks: Practical Stoicism for the 21st Century:
"Sickness is a Hindrance of the Body: You Always Have a Choice
Epictetus: 'Sickness is a hindrance to the body, but not to your ability to choose, unless that is your choice. Lameness is a hindrance to the leg, but not to your ability to choose. Say this to yourself with regard to everything that happens, then you will see such obstacles as hindrances to something else, but not to yourself.'"
That last part is important - your SELF, your Ruling Faculty, is not the same as your body. Something can hinder your leg, but not affect YOU. You are your Ruling Faculty, you are your own ability to choose. You are your soul, so to speak.
"Don't give up your Ruling Faculty, always consider what you are presented with carefully, and make the best decision from the choices available to you at the time.
Epictetus 'Remember that not he who gives ill language or a blow, insults, but the principle which represents these things as insulting. When, therefore, anyone provokes you, be assured that it is your own opinion which provokes you. Try, therefore, in the first place, not to be hurried away with the appearance. For if you once gain time and respite, you will more easily command yourself.'
Here Epictetus is using the same theory, that it is not the event but our opinions about the event that create our reaction to the event, to describe how it is possible to not go into things rashly in a knee-jerk way. So often when we are insulted, or something unforeseen and unfortunate happens, we go ahead and do something stupid that we later regret, often because we have misunderstood what has happened, or we were missing some important piece of information."