Deuteronomy 4:15-18
The Nature of Israel’s God
4:15 Be very careful, then, because you saw no form at the time the Lord spoke to you at Horeb from the middle of the fire.
4:16 I say this so you will not corrupt yourselves by making an image in the form of any kind of figure. This includes the likeness of a human male or female,
4:17 any kind of land animal, any bird that flies in the sky,
4:18 anything that crawls on the ground, or any fish in the deep waters of the earth.