Exodus 9:27-35

And Pharaoh sent, and called for Moses and Aaron, and said unto them, I have sinned this time: the LORD is righteous, and I and my people are wicked. Intreat the LORD (for it is enough) that there be no more 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 the LORD; and the thunder shall cease, neither shall there be any more hail; that thou mayest know how that the earth is the LORD's. But as for thee and thy servants, I know that ye will not yet fear the LORD God. And the flax and the barley was smitten: for the barley was in the ear, and the flax was bolled. But the wheat and the rie were not smitten: for they were not grown up. And Moses went out of the city from Pharaoh, and spread abroad his hands unto the LORD: 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, neither would he let the children of Israel go; as the LORD had spoken by Moses.