Exodus 3:12

3:12 He replied, “Surely I will be with you, and this will be the sign to you that I have sent you: When you bring the people out of Egypt, you and they will serve God on this mountain.”

Exodus 3:14

3:14 God said to Moses, “I am that I am.” And he said, “You must say this to the Israelites, ‘I am has sent me to you.’”