Passage 7.22.3
ἀφικόμενος οὖν περὶ ἑσπέραν ὁ τῷ θεῷ χρώμενος λιβανωτόν τε ἐπὶ τῆς ἑστίας θυμιᾷ καὶ ἐμπλήσας τοὺς λύχνους ἐλαίου καὶ ἐξάψας τίθησιν ἐπὶ τὸν βωμὸν τοῦ ἀγάλματος ἐν δεξιᾷ νόμισμα ἐπιχώριον--- καλεῖται δὲ χαλκοῦς τὸ νόμισμα---καὶ ἐρωτᾷ πρὸς τὸ οὖς τὸν θεὸν ὁποῖόν τι καὶ ἑκάστῳ τὸ ἐρώτημά ἐστι. τὸ ἀπὸ τούτου δὲ ἄπεισιν ἐκ τῆς ἀγορᾶς ἐπιφραξάμενος τὰ ὦτα· προελθὼν δὲ ἐς τὸ ἐκτὸς τὰς χεῖρας ἀπέσχεν ἀπὸ τῶν ὤτων, καὶ ἧστινος ἂν ἐπακούσῃ φωνῆς, μάντευμα ἡγεῖται.
Arriving around evening, the inquirer of the god burns incense upon the hearth, fills the lamps with oil, lights them, and places a local coin—called a chalkous—in the right hand upon the altar of the statue. He then whispers at the god’s ear whatever question each has in mind. After this, he departs from the marketplace, covering his ears completely. Having gone forth beyond it, he removes his hands from his ears, and the first voice he overhears he considers as the god’s oracle.