Sware unto them— That is, assured and promised them by an oath, that they should be safe under the protection and government of the Chaldeans.
Related Commentaries of Jeremiah 40:9
Jeremiah 40:9
9 And Gedaliah the son of Ahikam the son of Shaphan sware unto them and to their men, saying, Fear not to serve the Chaldeans: dwell in the land, and serve the king of Babylon, and it shall be well with you.