Plato, Laws 774c

ἀμυνέτω, μὴ βοηθῶν δὲ ὁ παραγενόμενος δειλός τε ἅμα καὶ κακὸς ὑπὸ τοῦ νόμου πολίτης εἶναι λεγέσθω.περὶ δὲ προικὸς εἴρηται μὲν καὶ πρότερον, εἰρήσθω δὲ πάλιν ὡς ἴσα ἀντὶ ἴσων ἐστὶν τὸ μήτε λαμβάνοντι μήτʼ ἐκδιδόντι διὰ χρημάτων ἀπορίαν γηράσκειν τοὺς πένητας· τὰ γὰρ ἀναγκαῖα ὑπάρχοντά ἐστι πᾶσι τῶν ἐν ταύτῃ τῇ πόλει, ὕβρις δὲ ἧττον γυναιξὶ καὶ δουλεία ταπεινὴ καὶ ἀνελεύθερος

and whoever is present and fails thus to give assistance shall be declared by law to be both a cowardly and a bad citizen. Concerning dowries it has been stated before, and it shall be stated again, that an equal exchange consists in neither giving nor receiving any gift, for all those who belong to this State have the necessaries of life provided for them; and the result of this rule will be less insolence on the part of the wives and less humiliation and servility on the part of the husband because of money.