Exodus 7:1-9

1 The LORD said to Moshe, "Behold, I have made you as God to Par`oh; and Aharon your brother shall be your prophet.
2 You shall speak all that I command you; and Aharon your brother shall speak to Par`oh, that he let the children of Yisra'el go out of his land.
3 I will harden Par`oh's heart, and multiply my signs and my wonders in the land of Mitzrayim.
4 But Par`oh will not listen to you, and I will lay my hand on Mitzrayim, and bring forth my hosts, my people the children of Yisra'el, out of the land of Mitzrayim by great judgments.
5 The Mitzrim shall know that I am the LORD, when I stretch forth my hand on Mitzrayim, and bring out the children of Yisra'el from among them."
6 Moshe and Aharon did so. As the LORD commanded them, so they did.
7 Moshe was eighty years old, and Aharon eighty-three years old, when they spoke to Par`oh.
8 The LORD spoke to Moshe and to Aharon, saying,
9 "When Par`oh speaks to you, saying, 'Perform a miracle!' then you shall tell Aharon, 'Take your rod, and cast it down before Par`oh, that it become a serpent.'"
The Hebrew Names Version is in the public domain.