Exodus 9:27-35

And Pharaoh sent, and called for Moses and Aaron, and said unto them, I have sinned this time: Jehovah is righteous, and I and my people are wicked. Entreat Jehovah; for there hath been enough of these mighty thunderings and hail; and I will let you go, and ye shall stay no longer. And Moses said unto him, As soon as I am gone out of the city, I will spread abroad my hands unto Jehovah; the thunders shall cease, neither shall there be any more hail; that thou mayest know that the earth is Jehovah’s. But as for thee and thy servants, I know that ye will not yet fear Jehovah God. And the flax and the barley were smitten: for the barley was in the ear, and the flax was in bloom. But the wheat and the spelt were not smitten: for they were not grown up. And Moses went out of the city from Pharaoh, and spread abroad his hands unto Jehovah: and the thunders and hail ceased, and the rain was not poured upon the earth. And when Pharaoh saw that the rain and the hail and the thunders were ceased, he sinned yet more, and hardened his heart, he and his servants. And the heart of Pharaoh was hardened, and he did not let the children of Israel go, as Jehovah had spoken by Moses.