Gedaliah is assassinated, then the Judeans flee to Israel for fear of reprisals from Nebuchadnezzar, even though Jeremiah tells them not to. Jeremiah is forced to go to Egypt with them, and he prophesies against them and Egypt when he gets there: 2 Kings 25:23–26; Jeremiah 40:11–43:13
Ignoring Jeremiah’s warnings to stay in Judah, the surviving Judeans fled to Egypt, afraid of what the Babylonians might do to them.
They settled in Tahpanhes, southwest of Port Said on this map. It isn’t too far from Goshen, the very place the Israelites had left several centuries earlier.
As one of the closest cities to Judea, it would have been a logical place for the refugees to settle.
Once they arrived, God told Jeremiah to do the following:
Jeremiah 43:9 While the people of Judah are watching, take some large rocks and bury them under the pavement stones at the entrance of Pharaoh’s palace here in Tahpanhes. Then say to the people of Judah, ‘This is what the Lord of Heaven’s Armies, the God of Israel, says: I will certainly bring my servant Nebuchadnezzar, king of Babylon, here to Egypt.
Nebuchadnezzar invaded within a couple of decades of this prophecy (in his 37th year; about 568 BC), an event noted by the king in his records (discovered and published in the late 1800s). (Source)
There’s nothing much left of Tahpanhes now. It has been renamed—the Greeks called it Daphnai, and the modern Arabs know the site as Def’neh. Excavations in 1886 found brickwork that was interpreted as the quadrangle at the entry of Pharaoh’s house in Tahpanhes’ in which Jeremiah buried the stones.