When God calls to Moses from the burning bush, He does so that knowing that Moses has spent the last forty years of his life as a simple shepherd in Midian. At one point, Moses tried to lead his people from bondage by killing an Egyptian and inspiring a revolt, but the people didn’t really respond like he thought.
It’s understandable that Moses will have some hesitation about the mission. He asks about his own qualifications (Exodus 3:11), then he asks for God’s identification (Exodus 3:13). In Exodus 4:1, Moses questions whether anyone will believe God has sent him, so God gives him two signs to show that God is behind him.
Every single question that Moses has asked, God has delivered…and then some. There is no logical reason why Moses should be stammering on about not going, unless he just really doesn’t want to.
The last two excuses from Moses show just how much Moses wants to stay in his life in Midian. He (lamely) tells God that he’s not a good public speaker, as if charisma and eloquence are a prerequisite for any great leader. Paul wasn’t good at speaking in public either, and he did just fine (2 Corinthians 10:10).
Then, the coup de grace: “Please God, just send someone else. Anyone else. Please” (Exodus 4:13).
What a stark contrast this statement is compared to his opening response. God calls out for Moses, and Moses responds with “Here I am.” He presents himself fully to God, using almost the exact same phrase that Isaiah will later use (Isaiah 6:8).
The main difference is that Isaiah’s ready to go wherever God needs him and do whatever God needs him to do. Moses, on the other hand, is more than just a little unsure of himself.
It’s worth pointing out that the Text doesn’t say that God is angry until Moses finally just begs God to send someone else. There, it says that “the anger of the Lord burned against Moses” (Exodus 4:14).
You know where else that phrase is used? When the people complained (Numbers 11:1), when the people worshipped Baal (Numbers 25:3), and when Uzziah touched the Ark of the Covenant (2 Samuel 6:7). Not great company for Moses.
I think it’s clear what God expected to happen here. Sure, Moses is nervous. Sure, he’ll have some reservations. Sure, he’ll want some help. And God is willing to give him all of those things and more!
But outright refusal to do what God is telling him to do? That’s something that makes God absolutely livid.