The Enchiridion, Section 32 — In Plain English

Epictetus — The Slave

When you go to see a fortune-teller, remember this: you don't know what will happen, and that's what you're asking about. But you already know what kind of thing it is before you go — if you think like a philosopher. If it's something outside your control, it can't be good or bad for you. So don't bring hope or fear to the fortune-teller. Don't go there shaking with worry. First understand that whatever happens doesn't really matter to you. It's all the same. You can handle any outcome well, and no one can stop you from doing that. Go confidently to the gods for advice. And when they give you guidance, remember who you asked for help. Remember whose advice you're ignoring if you don't follow it.

Epictetus — The Slave Original

When you have recourse to divination, remember that you know not what the event will be, and you come to learn it of the diviner; but of what nature it is you knew before coming; at least, if you are of philosophic mind. For if it is among the things not within our own power, it can by no means be either good or evil. Do not, therefore, bring with you to the diviner either desire or aversion—else you will approach him trembling—but first clearly understand that every event is indifferent and nothing to _you_, of whatever sort it may be; for it will be in your power to make a right use of it, and this no one can hinder. Then come with confidence to the gods as your counselors; and afterwards, when any counsel is given you, remember what counselors you have assumed, and whose advice you will neglect if you disobey.