οὐκ ἔστι λέουσι καὶ ἀνδράσιν ὅρκια πιστά → there are no pacts between lions and men, between lions and men there are no oaths of faith, there can be no covenants between men and lions
ἤισαν: Ἐπ. ἀντὶ ᾔεσαν, γ΄ πληθ. παρατ. τοῦ εἶμι (ibo).