Flavius Josephus, Antiquities of the Jews
William Whiston, A.M., Ed.

[176] Now while they were under this deliberation, Johanan, the son of Kareah, and the rulers. that were with him, came to Jeremiah the prophet, and desired that he would pray to God, that because they were at an utter loss about what they ought to do, he would discover it to them, and they sware that they would do whatsoever Jeremiah should say to them. And when the prophet said he would be their intercessor with God, it came to pass, that after ten days God appeared to him, and said that he should inform Johanan, and the other rulers, and all the people, that he would be with them while they continued in that country, and take care of them, and keep them from being hurt by the Babylonians, of whom they were afraid; but that he would desert them if they went into Egypt, and, out of this wrath against them, would inflict the same punishments upon them which they knew their brethren had already endured. So when the prophet had informed Johanan and the people that God had foretold these things, he was not believed, when he said that God commanded them to continue in the country; but they imagined that he said so to gratify Baruch, his own disciple, and belied God, and that he persuaded them to stay there, that they might be destroyed by the Babylonians. Accordingly, both the people and Johanan disobeyed the counsel of God, which he gave them by the prophet, and removed into Egypt, and carried Jeremiah and Barnch along with him.