τὸ λεγόμενον
From LSJ
Οὐκ ἔστιν οὐδὲν κτῆμα κάλλιον φίλου → Nulla est amico pulchrior possessio → Als einen Freund gibt's keinen schöneren Besitz
Greek > English (Woodhouse)
according to the adage, as the phrase is, as the saying goes, as the saying is, in common parlance