Ταῦτά μοι εἴρηται πρὸς ἀπόδειξιν τοῦ κατὰ τοὺς φωστῆρας μεγέθους, καὶ σύστασιν τοῦ μηδὲ μέχρι συλλαβῆς ἀργόν τι εἶναι τῶν θεοπνεύστων ῥημάτων· καίτοι γε οὐδενὸς ἥψατο σχεδὸν τῶν καιρίων ὁ λόγος· πολλὰ γὰρ περὶ μεγεθῶν καὶ ἀποστημάτων ἡλίου καὶ σελήνης ἐστὶν ἐξευρεῖν τοῖς λογισμοῖς, τὸν μὴ παρέργως τὰς ἐνεργείας αὐτῶν καὶ τὰς δυνάμεις ἐπεσκεμμένον. Εὐγνωμόνως οὖν δεῖ κατηγορεῖν ἡμᾶς τῆς ἑαυτῶν ἀσθενείας, ἵνα μὴ τῷ ἡμετέρῳ λόγῳ μετρῆται τῶν δημιουργημάτων τὰ μέγιστα, ἀλλὰ ἐξ ὀλίγων τῶν εἰρημένων παρ’ ἑαυτοῖς ἀναλογίζεσθαι, πόσα τινά ἐστι καὶ πηλίκα τὰ παρεθέντα.
I found this passage particularly challenging. I spent about twenty minutes trying to parse the final word (I should've used Google sooner)!
This post may serve as an inspiration (to someone) to look at some Greek and maybe even post a translation. If you want some help (I needed it!), use Blomfield Jackson's dynamic, 19th-century, public-domain translation I've copied below the cut.
I have entered into these details, to show you the grandeur of the luminaries, and to make you see that, in the inspired words, there is not one idle syllable. And yet my sermon has scarcely touched on any important point; there are many other discoveries about the size and distance of the sun and moon to which any one who will make a serious study of their action and of their characteristics may arrive by the aid of reason. Let me then ingenuously make an avowal of my weakness, for fear that you should measure the mighty works of the Creator by my words. The little that I have said ought the rather to make you conjecture the marvels on which I have omitted to dwell.