πέτραι συγχωροῦσαι

From LSJ

ἀλωπεκίζω πρὸς ἑτέραν ἀλώπεκα → Greek meets Greek | with the fox, be a fox

Source

Dutch (Woordenboekgrieks.nl)

‘de samenkomende rotsen’ (d.w.z. de Symplegaden) Eur. IT 124 (lyr.).