Now Moses was tending the flock of Jethro his father-in-law, the priest of Midian. And he led the flock to the back of the desert, and came to Horeb, the mountain of God. And the Angel of the Lord appeared to him in a flame of fire from the midst of a bush. So he looked, and behold, the bush was burning with fire, but the bush was not consumed. Then Moses said, “I will now turn aside and see this great sight, why the bush does not burn.” So when the Lord saw that he turned aside to look, God called to him from the midst of the bush and said, “Moses, Moses!” And he said, “Here I am.” Then He said, “Do not draw near this place. Take your sandals off your feet, for the place where you stand is holy ground.” Moreover He said, “I am the God of your father—the God of Abraham, the God of Isaac, and the God of Jacob.” And Moses hid his face, for he was afraid to look upon God. And the Lord said: “I have surely seen the oppression of My people who are in Egypt, and have heard their cry because of their taskmasters, for I know their sorrows.
Exodus 3:1-7 NKJV