Exodus 4:21-22

New Revised Standard Version Catholic Edition

²¹ And the Lord said to Moses, “When you go back to Egypt, see that you perform before Pharaoh all the wonders that I have put in your power; but I will harden his heart, so that he will not let the people go. ²² Then you shall say to Pharaoh, ‘Thus says the Lord: Israel is my firstborn son.