ἡ κέρκος τῇ ἀλώπεκι μαρτυρεῖ → you can tell a fox by its tail, small traits give the clue to the character of a person
see ῥύομαι.
ῥύσκευ: эп. (= ἐρύου) 2 л. sing. impf. к ῥύομαι.