Exodus 4:21

4:21 Yahweh said to Moses, "When you go back into Egypt, see that you do before Pharaoh all the wonders which I have put in your hand, but I will harden his heart and he will not let the people go.
-World English Bible

Other Translation

4:21 And the LORD said unto Moses, When thou goest to return into Egypt, see that thou do all those wonders before Pharaoh, which I have put in thine hand: but I will harden his heart, that he shall not let the people go.
-King James Version