Exodus 9:4-6

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