Charles Ellicott Commentary Jeremiah 50:38

"A drought is upon her waters, and they shall be dried up; for it is a land of graven images, and they are mad over idols." — Jeremiah 50:38 (ASV)

A drought is upon her waters. —Better, A sword. The Hebrew word for “drought” has the same consonants as that for “sword,” with different vowel-points. In the original text, the form of the two words must have been identical, as the vowel-points were of later introduction. The editors of the present text were probably guided by the thought that the context in this case determined the meaning of the word as “drought,” and not a “sword.” So in Deuteronomy 28:22, the text of the Authorized Version gives “sword,” and the margin “drought.” There is, however, a certain loss of rhetorical emphasis in the change of the word with which the three previous verses had begun. The “waters” include the canals of Babylon as well as the Euphrates.

They are mad upon their idols. —The word for “idols” means literally “terrors,” or “objects of terror,” as in Psalms 88:16; Job 20:25, and this is the only place in which it is used of the objects of worship. In Genesis 14:5; Deuteronomy 2:10–11 it appears as the name of the Emim, probably as meaning “the terrible, or gigantic ones.” Here it seems used for the colossal figures—winged bulls, human-headed lions, and the like—which were the objects of Babylonian worship. (See note on Jeremiah 49:16.)