Shemot 9:33-35

Orthodox Jewish Bible

³³ And Moshe went out of the Ir from Pharaoh, and spread out his palms [davening] unto Hashem; and the thunders and barad ceased, and the rain was not poured upon ha’aretz.

³⁴ And when Pharaoh saw that the rain and the barad and the thunders were ceased, he sinned yet more, and hardened his lev, he and his avadim.

³⁵ And the lev Pharaoh was hardened, neither would he let the Bnei Yisroel go; as Hashem had spoken by Moshe.