Exodus 3:12-14

12And God said, “Certainly I will be with you, and this shall be the sign to you that it is I who have sent you: when you have brought the people out of Egypt, you shall serve and worship God at this mountain.”

13Then Moses said to God, “Behold, when I come to the Israelites and say to them, ‘The God of your fathers (ancestors) has sent me to you,’ and they say to me, ‘What is His name?’ What shall I say to them?”

14God said to Moses, “I AM WHO I AM”; and He said, “You shall say this to the Israelites, ‘I AM has sent me to you.’ ”