οὐκ ἐπ' ἀρρήτοις γε τοῖς ἐμοῖς λόγοις

From LSJ

Τὸ γὰρ περισσὰ πράσσειν οὐκ ἔχει νοῦν οὐδένα → There is no sense in doing things beyond the usual measure

Sophocles, Antigone, 67-68