And the malach harevi'i (fourth angel) sounded his shofar; and a third of the shemesh (sun) was struck and a third of the levanah (moon) and a third of the kokhavim (stars), that a third of them might be darkened, and the yom (day) could not appear, and likewise the lailah (night). [SHEMOT 10:21-23; YECHEZKEL 32:7]