Shemot 11:8-10

Orthodox Jewish Bible

⁸ And all these thy avadim shall come down unto me, and bow down themselves unto me, saying, Get thee out, and kol HaAm that follow thee; and after that I will go out. And he went out from Pharaoh in a great anger.

⁹ And Hashem said unto Moshe, Pharaoh shall not pay heed unto you; that My mofetim may be multiplied in Eretz Mitzrayim.

¹⁰ And Moshe and Aharon did all these mofetim before Pharaoh; and Hashem hardened lev Pharaoh, so that he would not let the Bnei Yisroel go out of his land.