Plato, Laws 917c

ἁπλῆν δὲ εἰπών, ἂν μὴ τυγχάνῃ ταύτης, ἀποφέρων ὀρθῶς ἂν ἀποφέροι πάλιν, καὶ ταύτης τῆς ἡμέρας μὴ τιμήσῃ πλέονος μηδὲ ἐλάττονος, ἔπαινος δὲ ὅρκος τε περὶ παντὸς τοῦ πωλουμένου ἀπέστω· ἐὰν δέ τις ἀπειθῇ τούτοις, ὁ παρατυγχάνων τῶν ἀστῶν, μὴ ἔλαττον ἢ τριάκοντα γεγονὼς ἔτη, κολάζων μὲν τὸν ὀμνύντα ἀνατὶ τυπτέτω τις, ἀφροντιστῶν δὲ καὶ ἀπειθῶν ἔνοχος ἔστω ψόγῳ προδοσίας τῶν νόμων. τὸν δὲ δὴ κίβδηλόν τι πωλοῦντα, καὶ μὴ δυνάμενον τοῖς

he shall name one price only, and if he fails to get this, he will be entitled to take the article away; but he shall not put any other price, greater or less, upon it on that day; and there shall be no puffing or taking of oaths about anything put up for sale. If any man disobeys these rules, any townsman who is present, not being under thirty years of age, shall punish with a beating the seller who swears, and he shall do so with impunity; but if he is disobedient and neglects to do so, he shall be liable to reprobation for betraying the laws. And if a man is selling an adulterated article,