Exodus 9:5-7

Living Bible

⁵ The Lord announced that the plague would begin the very next day, ⁶ and it did. The next morning all the cattle of the Egyptians began dying, but not one of the Israeli herds was even sick. ⁷ Pharaoh sent to see whether it was true that none of the Israeli cattle were dead, yet when he found out that it was so, even then his mind remained unchanged and he refused to let the people go.