Exodus 9:4-6

But the LORD will make a distinction between the livestock of Israel and the livestock of Egypt, so that nothing will die of all that belongs to the sons of Israel.” ’ ” The LORD set a definite time, saying, “Tomorrow the LORD will do this thing in the land.” So the LORD did this thing on the next day, and all the livestock of Egypt died; but of the livestock of the sons of Israel, not one died.