καλῶς ποιεῖν

From LSJ

Ἐχθροῖς ἀπιστῶν οὔποτ' ἂν πάθοις βλάβην → Minus dolebis, quo hostibus credes minus → Dem Feind misstrauend bleibst von Schaden du verschont

Menander, Monostichoi, 164

Greek > English (Woodhouse)

treat well, use well