Charles Ellicott Commentary Exodus 9:5

"And Jehovah appointed a set time, saying, To-morrow Jehovah shall do this thing in the land." — Exodus 9:5 (ASV)

The Lord appointed a set time.—Since a plague on livestock is not uncommon in Egypt, especially in the Delta, and the coming affliction might therefore be ascribed by the Egyptians to natural causes, God took care to mark its miraculous character:

1. by appointing a time;
2. by exempting the cattle of Israel;
3. by making the disease fatal to all the cattle of the Egyptians that were left “in the field.”

Tomorrow.—The delay allowed any Egyptians who believed Moses to save their cattle by housing them.