Jeremiah 21:3-4

Jeremiah sent a message from the Lord back to the king through his messengers. The weapons of the defenders of Jerusalem would be ineffective. The Chaldean soldiers who were then besieging the city’s walls would penetrate it and enter the center of Jerusalem.

"The Babylonians (Chaldeans) were originally a seminomadic tribe living between northern Arabia and the Persian Gulf. In the tenth century B.C., the Assyrians gave the name Kaldu to the area formerly known as the ’Sea-Land’ [i.e., Mesopotamia]. . . Later, ’Chaldea’ was used to include Babylonia as a whole (cf. Ezekiel 23:23; Daniel 3:8)." [Note: Feinberg, p. 507. See also The New Bible Dictionary, 1962 ed., s.v. "Chaldaea, Chaldeans," by D. J. Wiseman.]