If you only had access to five chapters of the Bible, which five would you choose? Arguably, Exodus 3 should be on the list. It has the most stunning theophany, reveals the name of God and His way, the promise of God and salvation of a people, all the while establishing Moses as the key human figure in Israel's history.
[Robert Alter provides a rich commentary, in particular his longish reflection on the name of God. Hebrew is a foreign language, so you and I are dependent upon the work of others. Fox and Friedman also are wonderful.]
Moses is herding a flock. We must remember that David was herding a flock when Samuel came to call upon Jesse at God's direction (in fact, today that is the morning reading for the feast of St. Matthias!). The king/ruler/leaders are often depicted as shepherds in scripture, as is God. The symbolism is no doubt meant to be a focal point. Recall, in the previous chapter Moses had dispersed the abusive shepherds who were troubling the young woman. Here the father-in-law is called Jethro. Moses is "behind" (the literal meaning of the word, uncertain what it conveys, perhaps very deep?) "the wilderness" (preview of the sojourn with Israel) at "the Mountain of God" (called Horeb here, meaning 'parched' or 'dry'). The man of water is now meeting God in a dry place. The bush is unusual, most ancient Near East stories identified a sacred tree with a deity, perhaps the bush is a symbol of the humble nature of God or the downtrodden situation of the Israelites. Moses "sees and looks"; these words occur (6+3=9; "see' is used nineteen times in the first four chapters) frequently in the story. Initially we read it is a messenger (malak often translated as angel, it means one sent as an emissary. An angel will be present with the Israelites in their departure from Egypt and desert sojourn) in the flame in the bush, bur afterward God speaks. This is an issue of theology; must God's presence be mediated to appear on earth?
The bush is burning but not consumed. This is a mystery revealed but not explained. The fire image of God is found in Acts on Pentecost as well. "Flame" (labbah- only occurs here in Bible; it is related to lehabbah- which has the same meaning and occurs 19x including this interesting section of Isaiah 10: "The Light of Israel will be fire and its Holy One flame. It will burn and consume its thorns and and its thistles in a single day." This is a reference to God's vengeance on Assyria for its abuse of Israel.) and "fire" (later in Exodus the appearance of the Lord on the mountain will be compared to fire. The odd paradox draws Moses to the bush. Rapidly we read "see" three times. God calls to him (note the double use of the name) then demands he come no nearer and remove his sandals. The proper response to God is worship. Notice the balance of terror and intimacy, transcendence and immanence! He is on qodesh adamah. The "holy ground" (note: the word ground is the same one used of the creation of the "adam" in Genesis 2) is a new thing. Time had been consecrated by God (qadash, the root verb, has occurred only once, when God blessed the Sabbath; it is used 173x in the Jewish Bible) This is the first appearance of qodesh; it appears 470x total.
What comes next is a revelation of identity (v6-8). Hebrew does not usually use the verb "to be" (it is implied and supplied). There is a poetic resonance in Hebrew: "the God/elohim of ab (father), elohim abraham (father), elohim yitsak, elohim yaakov...afraid to look at elohim." [The reader is reminded that Eve looked at the tree and found it appealing, but afterwards they hid from God. The same verb for hid is used by Cain, that God would hide His face from Cain.] This voice belongs to the God of the Patriarchs. One wonders how much knowledge Moses had of the history and identity of the people. God reveals His experience. He has seen the affliction, heard their cry, and known their sufferings. God acts to save (He "comes down" to "deliver" them and "bring it up") His people. The same verb (natsal) in 2:19 referred to Moses saving the women at the well. God is not too far away or too busy to involve himself, The goal is to take them out of the depths of misery and raise them to the land promised to Abraham and his decendents, a lyrical land of abundance which is inhabited by Six Peoples. Once more the mention of Israel's cry and God sees the oppression Egypt oppresses on them. So Moses is sent ("apostle" in Greek), this implies that Moses has the authority of God for he will speak on His behalf. This is a classic "call narrative."
Theologically, we do well to note that God comes down to deliver by sending Moses. The human agency of God's salvation remains a constant theme in OT and NT. Jesus will send out the twelve in much the same manner, to save the people and deliver them from their oppression. The response of Moses is typical of other Biblical calls: reluctance. This is an important element because it indicates that Moses is not making a power grab. All Bible calling is "for the benefit of others" not for the one called. "Who am I?" Moses asks, and in a sense he then asks "Who are you?" (as we see above, He is the God of the Patriarchs, the God who pays attention and cares, the Savior God--but Moses wants a name!) The use of a "sign" is also common, and it is not rare that the exact reference of the sign is uncertain. It seems to be the liberation (take out) or the return to the holy (dry) mountain.
God's response to the question (13-14) is the musical ehyeh asher ehyeh. This seems to mean "I will be who/what I will be" or "I am who/what I am" Or "I will be who I am," "I am who I will be." There are many who translate it "I am who makes things be." Another view is that it is "He will be" (which is more common of Biblical names Isaac=he will laugh, Jacob=he will grab the heal, or he will protect, Jephthah=he will open, etc.) The connection of being and God's nature is a great philosophical and theological discussion. As many have said, "It is God's Nature to Be" which means "He is" describes who He is! Necessary (vs. contingent) Being is a difficult concept to grasp but the Ontological argument claims that God must be..... (It's worth looking up that one)
3:15 again God self identifies as the God of the three Patriarchs, then there is a line of poetry: shem (name, reputation, memorial) and zeker (memorial, remembrance) for endless time and all generations. This reinforces the YHWH--ehyeh translation.
What comes next is a foretelling of coming events. God will send for His people (under bondage) and bring them to the land promised to the Fathers. Once more we see the same six nations mentioned in the same order as inhabitants of the land. The whole people will listen (this is a bit more complex in the details) and the elders will join Moses with Pharaoh. The later narrative does not emphasize this point so much. They will say to Pharaoh "YHWH the Lord God of the Hebrews has met with us..." Note how the event with Moses is transferred to the whole people as an encounter! The phrase, "Lord God of the Hebrews struck me as odd, and I found it only occurs in Exodus. (3:18; 5:3; 7:16; 9:1; 9:13; 10:3). God of Israel is much more common.They will request a three day (resurrection!) journey into the wilderness to make a slaughter (for a sacrifice). The original request is to worship and leaves it open (but seems to imply) a return. However, the initial promise is to take them to a new land of promise! God knows Pharaoh will refuse (here it is on him alone). So God says He will "send (shalak) forth My hand" (verbal parallel to sending Moses). The interplay of human and divine continues. God knows that the wonders will make Pharaoh relent and he will "send" (shalak) the people away. However, the oppressed ones will leave with blessings God will give (nathan) them favor (chen=favor, grace; occurs 14x in Genesis, starting with Noah) and they will receive many gifts ("stripping Egypt"). This theme of Israel "plundering" the nations (as the Gentiles bring gifts to God's people) will appear elsewhere in the bible. Note that Paul seems to be acting on this when he implores the Gentile churches to bring a collection to Jerusalem for the poor. Many think this was, in his eyes, a fulfillment of Messianic prophecy!
As the chapter ends, we have a spoiler alert, for we already know how the story will end. However, the actual getting there is a long process and it is not smooth. One feels it is a demonstration of the challenge to faith and trust--believe God's promise and it will come to pass. Do not doubt even if it seems slow in coming. Trust! God delivers on His promise, but unbelief has a decidedly disastrous impact on who enjoys the promise fulfilled!