Plato, Laws 916a

δέκα ἡμέρας, ὁ δὲ πριάμενος ἴστω τὴν οἰκίαν τὴν τοῦ ἀποδομένου, τῶν περὶ τὰ τοιαῦτα ἐγκλημάτων εἰωθότων γίγνεσθαι χάριν καὶ τῶν ἀναγωγῶν τῶν κατὰ νόμους εἵνεκα· ἡ δὲ κατὰ νόμους ἀναγωγὴ καὶ μὴ τῇδε ἔστω. ἐάν τις ἀνδράποδον ἀποδῶται κάμνον φθόῃ ἢ λιθῶν ἢ στραγγουριῶν ἢ τῇ καλουμένῃ ἱερᾷ νόσῳ ἢ καὶ ἑτέρῳ τινὶ ἀδήλῳ τοῖς πολλοῖς νοσήματι μακρῷ καὶ δυσιάτῳ κατὰ τὸ σῶμα ἢ κατὰ τὴν διάνοιαν, ἐὰν μὲν ἰατρῷ τις ἢ γυμναστῇ, μὴ ἀναγωγῆς ἔστω τούτῳ

because of the charges which are commonly brought in connection with such transactions, and because of the acts of restitution permitted by law. Such legal restitution, or non-restitution, shall be on this wise:—If a man sell a slave who is suffering from phthisis or stone or strangury or the sacred disease (as it is called), or from any other complaint, mental or physical, which most men would fail to notice, although it be prolonged and hard to cure,—in case the purchaser be a doctor or a trainer, it shall not be possible for him to gain restitution for such a case, nor yet if the seller warned the purchaser of the facts.