ἐν τῇ ἡλικίᾳ εἶναι

From LSJ

ξένους ξένιζε, καὶ σὺ γὰρ ξένος γ' ἔσῃ → be hospitable to guests; you too will be a guest

Source

Greek > English (Woodhouse)

be of an age for service, be of military age