Commentary - Exodus 4:18-23

Bird's-eye view

In this crucial transitional passage, Moses moves from divine commission to obedient action. Having been called by God at the burning bush, he now sets his affairs in order and begins the journey back to Egypt. This section acts as a bridge, showing us the practical first steps of a world-altering mission. But more than that, it serves as a final briefing from the Sovereign Commander. God reiterates the mission's objective, anticipates the opposition, and declares His own role in orchestrating the entire conflict. The central revelation here is that God is not sending Moses into a fair fight. He is sending him as an ambassador to announce a verdict that has already been decided. The themes of God's absolute sovereignty over human hearts, the purpose of miracles as covenantal testimony, and the coming judgment as a righteous "measure for measure" reckoning are all laid out here in stark terms before the first plague is ever unleashed.

This is the divine strategy session. Moses is told that he will perform wonders, that Pharaoh will refuse to listen, and that God Himself will be the one strengthening Pharaoh's rebellious heart. This is all done so that the final confrontation can be framed exactly as God intends: a battle over the firstborn. God declares Israel to be His firstborn son, and because Pharaoh will refuse to release God's son, God will in turn take Pharaoh's son. The end is declared from the beginning, showcasing a God who is not reactive, but is the sovereign author of history, working all things, including the stubborn rebellion of kings, to accomplish His redemptive purpose.

Outline

Context In Exodus

This passage follows directly on the heels of Moses' dramatic encounter with God at the burning bush in Exodus 3, and the subsequent account of God equipping him for the task in Exodus 4:1-17. The theological foundation has been laid: Yahweh, the covenant God of Abraham, Isaac, and Jacob, has seen the affliction of His people and has come down to deliver them. Moses' objections have been answered, he has been given miraculous signs, and his brother Aaron has been appointed as his spokesman. Now, the narrative shifts from revelation to action. This section is the hinge upon which the story turns, moving Moses from the wilderness of Midian toward the court of Pharaoh. It sets the stage for the entire plague narrative by revealing God's overarching strategy, ensuring that when the events unfold, we understand them not as a back-and-forth struggle, but as the meticulous execution of a divine plan.

Key Issues

The Hardening of Pharaoh's Heart

One of the most profound and pastorally significant doctrines in all of Scripture is laid out here with crystalline clarity: God hardens hearts. Our modern, sentimental age wants to soften this, to explain it away, to make God into a frustrated bystander who simply "allows" Pharaoh to be stubborn. But the text is plain. God says, "I will harden his heart." The Hebrew verb chazaq means to strengthen, to make firm, to make resolute. God is not tempting Pharaoh to sin; Pharaoh's heart is already sinful and rebellious. What God is doing is strengthening Pharaoh's will in the direction it already wants to go. He is removing restraints, confirming him in his rebellion, and making him an unyielding adversary.

Why would God do this? The text itself provides the answer. He does it so that He can display His power not just in a simple release of the Israelites, but in a comprehensive judgment against the gods of Egypt (Exod 12:12). God is not interested in the path of least resistance. He is orchestrating a confrontation that will leave no doubt as to who is God. He is setting up a cosmic contest on the world stage that will echo through all of history. Pharaoh's hard heart, therefore, becomes an instrument, a tool, in the hand of God to bring about a far greater and more glorious redemption. This is not a problem for the doctrine of God's goodness; it is the very bedrock of it. Our God is so powerful and so wise that He weaves even the most defiant acts of sinful men into the tapestry of His perfect plan, all for His glory and the good of His people.

Verse by Verse Commentary

18 Then Moses went and returned to Jethro his father-in-law and said to him, “Please, let me go, that I may return to my brothers who are in Egypt and see if they are still alive.” And Jethro said to Moses, “Go in peace.”

Moses begins his mission not with a thunderous announcement, but with dutiful respect. He is under Jethro's authority as a son-in-law and an employee, and he honors that structure. He doesn't simply abandon his flock and family. This is a mark of righteousness. Further, his request is framed with wisdom and discretion. He states his purpose in simple, human terms: to check on his relatives. He is not being deceptive; he is simply not obligated to recount his entire supernatural encounter to a man who, at this point, is still a priest of Midian. God's call does not obliterate our earthly responsibilities, but rather consecrates them. Jethro's response, "Go in peace," is a standard blessing, but within the narrative it functions as God's providential release. The first human hurdle is cleared.

19 And Yahweh said to Moses in Midian, “Go, return to Egypt, for all the men who were seeking your life are dead.”

Here we see the tender care of God for His servant. God knows Moses' fears. Forty years prior, Moses had fled Egypt as a wanted man, a murderer in the eyes of the state. It is one thing to face the current Pharaoh, but it would be another to face him while also dodging bounty hunters from the old regime. God removes this specific, lingering fear. He tells Moses that the coast is clear. This is a practical grace. God does not just issue commands from on high; He walks with His people, understands their anxieties, and often clears the path before them in ways they could not have anticipated. He deals with the warrants for our arrest.

20 So Moses took his wife and his sons and mounted them on a donkey and returned to the land of Egypt. Moses also took the staff of God in his hand.

This is the picture of faith in action. The man who was once a prince of Egypt, accustomed to chariots, now leads his family on a single donkey. This is a humble procession. The kingdom of God often advances in ways that look foolish and weak to the world. But Moses carries with him the one thing that matters: "the staff of God." This simple shepherd's tool, the instrument of his mundane labor, has now been consecrated as the instrument of divine power. It is a tangible symbol that the success of this mission depends not on Moses' eloquence, his resources, or his strategy, but solely on the authority and power of the God who sent him. He is returning to Egypt not with an army, but with a stick. And it is more than enough.

21 And Yahweh said to Moses, “When you go to return to Egypt, see to it that all the miraculous wonders which I have put in your hand, that you do them before Pharaoh; but as for Me, I will harden his heart with strength so that he will not let the people go.

This is the divine intelligence briefing, and it is staggering. First, the purpose of the miracles is defined. They are to be performed "before Pharaoh." They are a formal, public testimony, a presentation of God's credentials. They are not primarily to persuade Pharaoh, but to indict him. They will leave him without excuse. Second, God declares His own active, sovereign role in the opposition. The English translation "I will harden his heart" is exactly right. God is not a passive observer. He is going to strengthen Pharaoh in his rebellion. This is to prevent a premature surrender. God wants this conflict to go the distance, so that His power can be fully and gloriously displayed. God is setting the stage for a masterpiece of judgment and redemption, and a hard-hearted Pharaoh is a necessary part of the set design.

22 Then you shall say to Pharaoh, ‘Thus says Yahweh, “Israel is My son, My firstborn.

Moses is given the opening line of the lawsuit. He is to speak as a true ambassador, prefacing his message with "Thus says Yahweh." The content of the message is a declaration of ownership based on a relationship of love. "Israel is My son, My firstborn." This is the first time in Scripture that God refers to the nation of Israel with this title. In the ancient world, the firstborn was the principal heir, the representative of the father. This is a claim of unique privilege and deep affection. It is also a direct challenge to Pharaoh, who was considered the son of Ra. God is declaring that He has a son, and His son is currently making bricks for the false son of a false god.

23 So I said to you, ‘Let My son go that he may serve Me’; but you have refused to let him go. Behold, I will kill your son, your firstborn.” ’ ”

The ultimatum is laid out with terrifying clarity. The demand is for release, and the purpose of that release is worship: "that he may serve Me." The conflict is fundamentally about lordship. Then, God states Pharaoh's response as a settled fact: "you have refused." The judgment is then announced, and it is a perfect example of lex talionis, or measure-for-measure justice. Because you will not release My firstborn son, I will kill your firstborn son. The final, most devastating plague is not a vindictive afterthought; it is the just sentence for the primary crime, announced before the trial even begins. This shows that God is in complete control. He is not reacting to Pharaoh; Pharaoh is reacting to a script God has already written. The warning is severe, but it is also gracious. Pharaoh is being told the full consequences of his actions before he takes them. He will not be able to say he was not warned.

Application

First, we must embrace the doctrine of God's absolute sovereignty, not as a harsh and scary thing, but as our deepest comfort. The God who hardened Pharaoh's heart for His good purposes is the same God who is working all things, including the opposition we face, for our good. No opposition to the church is a surprise to Him. The most stubborn and powerful enemies of the gospel are nothing more than tools in His hand, which He uses to accomplish a redemption far more glorious than we could engineer on our own.

Second, we must understand that the central conflict of our age is the same as it was in Moses' day. It is a battle over sonship and worship. The world, like Pharaoh, wants to claim our children, our time, our allegiance, and our labor for its own purposes. God's declaration still stands: "This is My son, this is My daughter. Let them go, that they may serve Me." Our task as parents, as pastors, and as Christians is to continually press this claim against a world that wants to enslave us and our children in its brick pits.

Finally, we see the principle of substitutionary justice prefigured here. The conflict is resolved by the death of a firstborn. Pharaoh refuses to release God's son, so his own son dies. This points us directly to the cross. We were all enslaved to sin, and God sent His true Ambassador to demand our release. But the price was not the death of our enemy's son, but the death of His own. God's true and only Firstborn, Jesus Christ, was killed so that we, the adopted sons, might be set free to serve Him. The justice of God that fell on Egypt is the same justice that fell on Christ at Calvary. For those who are in Christ, the angel of death has passed over. For those who, like Pharaoh, refuse to bow, that same justice remains.