Hastings' Dictionary of the Bible (1898)
HILL, HILLS. There is some confusion in the use of "hill" and "mountain" in the A.V. Thus the "hill country" of Luke 1:39 is the "mountain of Judah," Josh 20:7. Again, precisely the same elevation is called both mountain and hill, Luke 9:28; cf. 1 Chr 9:37. But the original text is exact, employing words of quite different meaning to express the different elevations of hills and mountains. See Palestine, Mountain.