Flight to Pella
The fourth-century church fathers Eusebius and Epiphanius of Salamis cite a tradition that before the destruction of Jerusalem in AD 70 the Jerusalem Messianic Jews had been warned to flee to Pella in the region of the Decapolis across the Jordan River. The flight to Pella probably did not include the Ebionites. The authenticity of this tradition has been a much debated question since 1951 when S. G. F. Brandon in his work "The Fall of Jerusalem and the Messianic Jewish Church" provided strong arguments against it, arguing that the Messianic Jews would have been allied  to their compatriots, the Zealots; only after the destruction of the Jewish community would Messianic Judaism have emerged as a universalist religion. The Christian–Zealot alliance has hardly been taken seriously, but the historicity of the flight to Pella has been controversial ever since.