A common expression with the prophets (Isa. 2:12; 13:6; Eze. 30:3; Amos 5:18; Zeph. 1:14; etc.). For the significance of the expression see on Isa. 13:6. Primarily, Joel is referring to the impending judgments upon Judah. In principle his predictions apply also to the final day of judgment to come upon the world (see pp. 37, 38).