Exodus 9:4-7

But the LORD will treat Israel’s animals differently from the animals of Egypt. None of the animals that belong to the Israelites will die. The LORD has set tomorrow as the time he will do this in the land.’ ” The next day the LORD did as he promised. All the farm animals in Egypt died, but none of the animals belonging to Israelites died. The king sent people to see what had happened to the animals of Israel, and they found that not one of them had died. But the king was still stubborn and did not let the people go.