Swelling of Jordan

(Jeremiah 12:5), literally the “pride” of Jordan (as in Revised King James Version), i.e., the luxuriant thickets of tamarisks, poplars, reeds, etc., which were the lair of lions and other beasts of prey

The reference is not to the overflowing of the river banks. (Compare 49:19; 50:44; Zechariah 11:3).