Acts 7:30-34

30“After forty years had passed, an angel appeared to him in the wilderness of Mount Sinai, in the flame of a burning thorn bush.

31When Moses saw it, he was astonished at the sight; but as he went near to look more closely, the voice of the Lord came [to him, saying]:

32‘I am the God of your fathers, the God of Abraham and of Isaac and of Jacob.’ Moses trembled with fear and did not dare to look.

33Then the Lord said to him, ‘Remove the sandals from your feet, for the place where you are standing is holy ground [worthy of reverence and respect].

34I have most certainly seen the oppression of My people in Egypt and have heard their groaning, and I have come down to rescue them. Now come, and I will send you to Egypt [as My messenger].’