And the LORD set a time, saying, “Tomorrow the LORD will do this thing in the land.”
Here is, I. Warning given of another plague, namely, the murrain of beasts. When Pharaoh's heart was hardened, after he had seemed to relent under the former plague, then Moses is sent to tell him there is another coming, to try what that would do towards reviving the impressions of the former plagues.
Commenting on Exodus 9:1-7
And the Lord appointed a set time,.... For the coming of this plague, that it might plainly appear it came from him, and was not owing to any natural cause: saying, tomorrow the Lord shall do this thing in the land; thus giving him time and space, as he had often done before, to consider the matter well, repent of his obstinacy, and dismiss the...
To-morrow the Lord shall do this - By thus foretelling the evil, he showed his prescience and power; and from this both the Egyptians and Hebrews must see that the mortality that ensued was no casualty, but the effect of a predetermined purpose in the Divine justice.