Adam Clarke on Jeremiah 46:18

As Tabor is among the mountains - This mountain is situated in the plain of Esdraelon in Galilee, on the confines of the tribes of Zebulun and Issachar, Jos 19:22. It stood by itself, separated from all the other mountains by deep valleys, and is the highest of the whole.

And as Carmel by the sea - Carmel is a mountain on the coast of the Mediterranean Sea, on the southern frontier of the tribe of Asher. Were the Egyptians as distinguished for valor and strength as the mountains Tabor and Carmel are for height among the other mountains in their vicinity, they should not be able to stand the shock of the Chaldean army.