Exodus 9:1-3

Then the LORD said to Moses, ‘Go to Pharaoh and say to him, “This is what the LORD, the God of the Hebrews, says: ‘Let my people go, so that they may worship me.’ If you refuse to let them go and continue to hold them back, the hand of the LORD will bring a terrible plague on your livestock in the field – on your horses, donkeys and camels and on your cattle, sheep and goats.