Moses is tending the flocks of Jethro and comes to Horeb, the mountain of Elohim
Exodus 3:2 And the angel of Jehovah appeared unto him in a flame of fire out of the midst of a bush: and he looked, and, behold, the bush burned with fire, and the bush was not consumed.
The messenger of Yahweh "appears" to Moses in a flame in the midst of the bush, meaning Moses could see this messenger of Yahweh. In verse 3 Moses goes to check out this bush.
Exodus 3:4 And when Jehovah saw that he turned aside to see, God called unto him out of the midst of the bush, and said, Moses, Moses. And he said, Here am I.
In the previous verse it was the messenger of Yahweh who was in the midst of the bush, but here it is Elohim. According to this text the messenger of Yahweh is Elohim. In verses 5 and 6 Elohim speaks with Moses and again claims to be Elohim, the Elohim of his fathers.
Exo 3:7 And Jehovah said, I have surely seen the affliction of my people that are in Egypt, and have heard their cry by reason of their taskmasters; for I know their sorrows;
We already know that the messenger of Yahweh, who is in the midst of the bush, is the Elohim who is speaking to Moses. Now in this verse this Elohim is identified as Yahweh.