Pseudo-Clementines (2—3rd century)
“Subsequently also an evident proof of this great mystery is supplied in the fact, that every one who, believing in this Prophet who had been foretold by Moses, is baptized in His name, shall be kept unhurt from the destruction of war which impends over the unbelieving nation, and the place itself; but that those who do not believe shall be made exiles from their place and kingdom, that even against their will they may understand and obey the will of God.” (Recognitions 1:39:3)
Eusebius
“But the people of the church in Jerusalem had been commanded by a revelation, vouchsafed to approved men there before the war, to leave the city and to dwell in a certain town of Perea called Pella.” (History of the Church 3:5:3)
"The whole body, however, of the church at Jerusalem, having been commanded by a divine revelation, given to men of approved piety there before the war, removed from the city, and dwelt at a certain town beyond the Jordan, called Pella. Here those that believed in Christ, having removed from Jerusalem, as if holy men had entirely abandoned the royal city itself, and the whole land of Judea; the divine justice, for their crimes against Christ and his apostles finally overtook them, totally destroying the whole generation of these evildoers from the earth. (Eusebius, 3:5.)
“After all those who believed in Christ had generally come to live in Perea, in a city called Pella of the Decapolis of which it is written in the Gospel and which is situated in the neighborhood of the region of Batanaea and Basanitis, Ebion’s preaching originated here after they had moved to this place and had lived there.” (Panarion 30:2)
"For when the city was about to be captured and sacked by the Romans, all the disciples were warned beforehand by an angel to remove from the city, doomed as it was to utter destruction. On migrating from it they settled at Pella, the town already indicated, across the Jordan. It is said to belong to Decapolis (de Mens. et Pond., 15).
“Now this sect of Nazarenes exists in Beroea in Coele-Syria, and in Decapolis in the district of Pella, and in Kochaba of Basanitis–called Kohoraba in Hebrew. For thence it originated after the migration from Jerusalem of all the disciples who resided at Pella, Christ having instructed them to leave Jerusalem and retire from it on account of the impending siege. It was owing to this counsel that they went away, as I have said, to reside for a while at Pella” (Haer 29:7).
"For when all who believed in Christ had settled down about that time in Peraea, the majority of the emigrants taking up their abode at Pella, a town belonging to the Decapolis mentioned in the Gospel, near Batanea and the district to Basanitis, Ebion got his excuse and opportunity. At first their abode was Kochaba, a village in the district of Carnaim, Arnem, and Astaroth, in the region of Basanitis, according to the information we have received. But I have spoken, in other connections and with regard to other heresies, of the locality of Kochaba and Arabia (Haer 30:2)… “[The Ebionites] spring for the most part from Batanea … and Paneas, as well as from Moabitis and Cochaba in Basanitis on the other side of Adraa” (Haer 30:18).
Epiphanius
“The Nazoraean sect exists in Beroea near Coele Syria, in the Decapolis near the region of Pella, and in Bashan in the place called Cocaba, which in Hebrew is called Chochabe. That is where the sect began, when all the disciples were living in Pella after they moved from Jerusalem, since Christ told them to leave Jerusalem and withdraw because it was about to be besieged. For this reason they settled in Peraea and there, as I said, they lived. This is where the Nazoraean sect began.” (Panarion 29:7:7-8)
“Their sect began after the capture of Jerusalem. For when all those who believed in Christ settled at that time for the most part in Peraea, in a city called Pella belonging to the Decapolis mentioned in the gospel, which is next to Batanaea and the land of Bashan, then they moved there and stayed…” (Panarion 30:2:7)
"For when the city was about to be captured and sacked by the Romans, all the disciples were warned beforehand by an angel to remove from the city, doomed as it was to utter destruction. On migrating from it they settled at Pella, the town already indicated, across the Jordan. It is said to belong to Decapolis " (On Weights and Measures 15)
Eutychius of Alexandria
“Qistus, governor of Jerusalem, died and the city was without any authority or sovereign to govern it. The Jews then arose and rioted and killed James, son of Joseph, known as the “brother of the Lord”, stoning him to death. Then they harassed a group of disciples and expelled them from the city. The Christians abandoned Jerusalem, crossed the Jordan and settled in those places. Informed of this fact, Nero Caesar sent word to the commander stationed in the East, named Vespasian, to rally his troops and go to Judea with orders to kill all the inhabitants, sparing none, and to destroy the houses.” (The Annals of Eutychius of Alexandria, ch. 9:)