Epictetus, Works, book 2, Περὶ τῆσ τοῦ λέγειν δυνάμεωσ. 4:

καὶ ποῖοσ ἄγγελοσ οὕτωσ ὠκὺσ καὶ ἐπιμελήσ; εἰκῇ δὲ καὶ τὸν μεταξὺ ἀέρα οὕτωσ ἐνεργὸν ἐποίησεν καὶ ἔντονον, ὥστε δι’ αὐτοῦ τεινομένου πωσ διικνεῖσθαι τὴν ὁρ́ασιν; εἰκῇ δὲ φῶσ ἐποίησεν, οὗ μὴ παρόντοσ οὐδενὸσ τῶν ἄλλων ὄφελοσ ἦν;