Moses lives as a shepherd in Midian. He watches over the herd of his father-in-law Jethro. Previously, when he was about forty years old, he had made an attempt to make the people of Israël revolt against the oppressive regime of the Egyptians. At that attempt he had killed an Egyptian. However, he had failed to gather the people behind him. Acts 7 verse 23 to 28.
Compare John 1 verse 11.
Moses then fled to Midian.
Now he leads the herd near to mount Horeb, and notices something special: a burning bush. Though the bush is on fire, it does not burn up.
God, the Angel of the Lord, reveals Himself in the fire. He commands Moses:
"Take off your sandals, for the place where you are standing is holy ground".
Moses is overwhelmed by the presence of God and dares not look at Him.
God, Jahweh, introduces Himself as the God of his ancestors, and says to Moses:
"I have indeed seen the misery of my people in Egypt. I have heard them crying out".
The Lord remembers His covenant with Abraham, Isaac and Jacob.
Exodus 2 verse 24.
Moses’ mission will be to go to the pharaoh, and to lead the people of Israël out of Egypt, according to the promise God gave Abraham in Genesis 15.
Moses remembers his previous failed attempt to gather the people behind him and makes objections. He considers himself incapable and fears that the people will not believe that he acts on behalf of God.
The Lord is merciful towards Moses and meets his concerns. He is allowed to go to the pharaoh in the company of his brother Aaron.
This time God will make the exodus come to pass!
In many places in the Bible fire is an image of the divine presence.
Genesis 15 verse 17.
Exodus 19 verse 18.
Psalm 18 verse 9.
The burning bush is an image of the suffering yet preserved people of Israël. An image of the eternal God, living in the midst of His people, purifying and preserving it.
Zechariah 2 verse 5.
Deuteronomy 4 verse 20 calls Egypt 'the iron-smelting furnace, that is the purging and testing fire'.
About four hundred years earlier God lead Jacob and his offspring to Egypt, where the abundance of grain made the people flourish and multiply.
At the end of this era the Egyptian oppression made the people yearn for the promised land of milk and honey.