πρὸς μητρός μητρόθεν

From LSJ

Αὐτάρκης ἔσῃ, ἂν μάθῃς τί τὸ καλὸν κἀγαθόν ἐστι → You will be contented with your lot if you learn what the honourable and good is

Plutarch, De virtute et vitio

Greek > English (Woodhouse)

on the mother's side