Epictetus, Encheiridion, 17
“Remember that you are an actor in a drama, whatever kind the playwright desires. If he wishes it to be short, it is short. If he wants it to be long, it is long.
If he wants you to act as a beggar, act even that part seriously. And the same if you are a cripple, a ruler, or a fool. This is your role: to play well the part you were given. It is another’s duty to choose.”
Μέμνησο, ὅτι ὑποκριτὴς εἶ δράματος, οἵου ἂν θέλῃ ὁ διδάσκαλος· ἂν βραχύ, βραχέος· ἂν μακρόν, μακροῦ· ἂν πτωχὸν ὑποκρίνασθαί σε θέλῃ, ἵνα καὶ τοῦτον εὐφυῶς ὑποκρίνῃ· ἂν χωλόν, ἂν ἄρχοντα, ἂν ἰδιώτην. σὸν γὰρ τοῦτ᾿ ἔστι, τὸ δοθὲν ὑποκρίνασθαι πρόσωπον καλῶς· ἐκλέξασθαι δ᾿ αὐτὸ ἄλλου.
On Facebook M. L Lech let me know that this sentiment appeared in the work of an earlier cynic philosopher
Teles the Philosopher, On Self-Sufficiency (Hense, 5)
“Just as a good actor will carry off well whatever role the poet assigns him, so too a good person should manage well whatever chance allots. For chance, as Biôn says, just like poetry, assigns the role of the first speaker and the second speaker, now a king and then a vagabond. Don’t long to be the second speaker when you have the role of the first. Otherwise, you will create disharmony.”
Δεῖ ὥσπερ τὸν ἀγαθὸν ὑποκριτὴν ὅ τι ἂν ὁ ποιητὴς περιθῇ πρόσωπον τοῦτο ἀγωνίζεσθαι καλῶς, οὕτω καὶ τὸν ἀγαθὸν ἄνδρα ὅ τι ἂν περιθῇ ἡ τύχη. καὶ γὰρ αὕτη, φησὶν ὁ Βίων, ὥσπερ ποιήτρια, ὁτὲ μὲν πρωτολόγου, ὁτὲ δὲ δευτερολόγου περιτίθησι πρόσωπον, καὶ ὁτὲ μὲν βασιλέως, ὁτὲ δὲ ἀλήτου. μὴ οὖν βούλου δευτερολόγος ὢν τὸ πρωτολόγου πρόσωπον· εἰ δὲ μή, ἀνάρμοστόν τι ποιήσεις.