Albert Barnes Commentary Jeremiah 42:7

"And it came to pass after ten days, that the word of Jehovah came unto Jeremiah." — Jeremiah 42:7 (ASV)

After ten days - On previous occasions Jeremiah when consulted answered at once (Jeremiah 21:3). The present delay was probably granted by God in order to free the minds of the people from the panic caused by the murder of Gedaliah and their fear of Chaldaean vengeance. Jeremiah could have had no doubt that the flight into Egypt was contrary to the tenor of his former prophecies.