New Defender's Study Bible Notes
3:2 angel of the LORD. This is clearly a theophany, one of the pre-incarnate appearances of the divine Word. Later verses stipulate that God, not a created angel, was speaking to Moses (e.g., Exodus 3:4).
3:3 this great sight. The sight of the bush burning in a desert was, no doubt, quite an ordinary sight. The fact that the bush was not consumed by the flame, however, was obviously miraculous. In modern scientific terminology, the laws of thermodynamics were being violated, and these are the most inviolable of all scientific laws.
3:4 Moses, Moses. When God calls a name twice, it is clear that the occasion is of great importance, as here when He called Moses. Note also the double calls: “Abraham, Abraham” (Genesis 22:11); “Samuel, Samuel” (I Samuel 3:10); “Simon, Simon” (Luke 22:31,32); “Saul, Saul” (Acts 9:4); and “Jerusalem, Jerusalem” (Matthew 23:37,38).