A Reformed Defense of Concurrence from Isaiah 10
Isaiah 10:5–15 is the locus classicus of concurrence in the Old Testament. The doctrine is not imposed upon this text but arises naturally and necessarily from it.
The doctrine of divine concurrence—that God actively works as the first cause in and through the actions of secondary causes, including sinful ones—does not merely find incidental support in Isaiah 10. It rises from the text’s own grammar, imagery, and theological logic with a force that renders competing interpretations exegetically untenable.
Both the Westminster Confession of Faith (5.2, 5.4) and the 1689 London Baptist Confession (5.2, 5.4) explicitly cite Isaiah 10:6–7, 12 as proof texts for the doctrine that God’s providence extends even to sinful human actions—“and that not by a bare permission.”
Verse 5
The Hebrew is grammatically emphatic. The word shēvet (שֵׁבֶט, “rod,” from a root meaning “to strike”) appears in construct with ’appî (“my anger”), and maṭṭeh (“staff”) is linked to za’mî (“my indignation”)—both terms bearing God’s first-person possessive suffix. Assyria is not described as a rod of its own anger. The grammar establishes an ontological relationship of instrumentality: Assyria belongs to God as a tool belongs to its wielder.
“All the strength which the enemy shall possess proceeds from the wrath of God, and they are moved by his secret impulse to destroy the people, for otherwise he would not move a finger.”
“The staff in their hand, wherewith they smite his people, is his indignation; it is his wrath that puts the staff into their hand and enables them to deal blows at pleasure.”
The power is God’s; the hand is Assyria’s; the result is one unified act with two distinct agents operating at different causal levels.
A God who merely permits does not call the permitted agent “My rod.” One does not describe a runaway horse as “my vehicle.” The possessive language presupposes ownership, direction, and purposive deployment—not passive toleration.
Assyria was “made use of by him as an instrument to chastise and correct Israel for their sins,” and the staff with which they smote Israel “was no other than the wrath and indignation of God against that people, and the execution of it, which he committed to them as instruments.”
Verse 6
Two Hebrew verbs anchor this verse. The first, ’ăshallecḥennû (אֲשַׁלְּחֶנּוּ), is the Pi’el imperfect of shālach—the identical verb used for God sending Moses (Ex. 3:12), sending prophets (Isa. 6:8), sending angels (Gen. 24:7), and sending plagues against Egypt (Ex. 9:14). The Pi’el stem intensifies the action. The second, ’ăṣawwennû (אֲצַוֶּנּוּ), is the Pi’el of tsāwāh, the standard verb for a sovereign’s authoritative command—the same word used when God commands Adam (Gen. 2:16), Moses (Ex. 34:11), and Joshua (Josh. 1:9). Both verbs are first-person singular with God as their grammatical and theological subject.
If shālach is metaphorical here, then it must be metaphorical when God “sends” Moses or “sends” Isaiah—a conclusion no interpreter is prepared to accept. The verb carries its ordinary force of purposive dispatch.
God “bends them to execute his judgments, just as if they carried their orders engraven on their minds.”
God’s commission to Assyria was “not by any legal commission, or express command, but by the secret power of his providence, guiding and directing him into the land of Judea, to ravage and spoil it.”
This distinction is critical. The Reformed tradition has never claimed that God whispered instructions into Sennacherib’s ear. The “command” operates through providential governance—God arranges circumstances, inclines hearts, and directs events so that the Assyrian freely acts precisely as God has decreed. This is the heartbeat of concurrence: the first cause works through the secondary cause according to the secondary cause’s own nature.
God’s concurrence is “not general and indifferent, but particular, specific and immediate.”
It is an error to claim “that it consists merely in a general communication of power, without determining the specific action in any way”—a view he attributed to “Jesuits, Socinians, and Arminians.”
Verse 7
This single verse contains the entire architecture of concurrence in miniature. God’s intention (vv. 5–6) is the righteous discipline of a covenant-breaking people. Assyria’s intention (v. 7) is rapacious imperial expansion. The same physical event—the invasion of Israel—is simultaneously the execution of God’s holy decree and the expression of Assyria’s sinful ambition. Neither intention cancels the other. Neither agent is redundant.
“With his almighty power God makes possible every secondary cause and is present in it with his being at its beginning, progression, and end. It is he who posits it and makes it move into action (praecursus) and who further accompanies it in its working and leads it to its effect (concursus).”
God “works with such amazing skill that he brings men to yield obedience to him, even without their knowledge or will.” He identified three modes: all creatures move by Him; He specially impels the wicked as He sees fit; He guides the elect by His Spirit.
“He did not imagine that he was only the rod of his anger, and the staff of his indignation, a minister of his wrath, and the executioner of his vengeance; he thought he was his own lord and master, and acted by his own power.”
The parallel with Genesis 50:20 is structurally exact: “You meant evil against me, but God meant it for good.” Acts 2:23 applies the same structure to the cross itself: Christ was “delivered over by the predetermined plan and foreknowledge of God,” yet crucified “by the hands of godless men.” The dual-intention structure is not a later theological imposition but a pervasive biblical category.
Verses 12–15
The invasion is called God’s “work” (ma’aseh). Not Assyria’s work that God tolerated. God’s work that Assyria executed. This attribution is inexplicable under a bare permission framework. One does not call an event one merely tolerated “my work.”
The logical structure of verses 5–12 is devastating to the mere-permission thesis:
God pronounces “Woe” on Assyria (v. 5a)—Assyria is under judgment.
God claims Assyria as “My rod” and “My staff” (v. 5b)—Assyria is God’s instrument.
God says “I send him” and “I command him” (v. 6)—God dispatches the instrument.
Assyria intends something different from what God intends (v. 7)—the dual intention.
Assyria boasts of its own power (vv. 8–11, 13–14)—the instrument claims independence.
God will punish Assyria’s arrogance after finishing His own work (v. 12)—the wielder judges the tool.
This sequence only makes sense if God was actively governing the invasion. If God merely permitted Assyria to act, there would be no basis for calling the invasion “his work.” If God merely stood aside, Assyria’s boast—“By the strength of my hand I have done it, and by my wisdom”—would be substantially correct.
“God sometimes makes wicked men the instruments of his will… the actions of men, so far as they are natural, are from God; but so far as they are sinful, they are from men themselves, and God has no hand at all in them.”
The Capstone
Four instruments—axe, saw, rod, staff—each set against its user. The Hebrew phrase lō’ ’ēts (“the not-wood”) designates the wielder as ontologically superior: one made of wood, the other not. The analogy works only if God is the one who hews, wields, lifts, and holds. If God merely permitted Assyria to act on its own, the analogy collapses. A person who merely permits an axe to chop does not “hew with it.”
“The king of Assyria… was only an instrument in the hand of God, like an axe in the hand of one that hews down trees; and therefore it was vain and ridiculous to take that to himself which belonged to the Lord, on whom he depended as an instrument, as to motion, operation, and effect; from whom he had all power to act, all fitness for it, and efficacy in it, as the axe has from the person that makes and uses it.”
That extraordinary sentence—Assyria depended on God “as to motion, operation, and effect”—is a precise philosophical statement of concursus, echoing the scholastic language of God’s concurrence in all creaturely operations.
“God frequently exclaims, that by his hiss, by the clang of his trumpet, by his authority and command, the wicked are excited to war. He calls the Assyrian the rod of his anger, and the axe which he wields in his hand.” Then his devastating conclusion: “It is the merest trifling to substitute a bare permission for the providence of God, as if he sat in a watch-tower waiting for fortuitous events, his judgments meanwhile depending on the will of man.”
The inclusio between verse 5 and verse 15—both employing shēvet (“rod”) and maṭṭeh (“staff”)—frames the entire oracle as a meditation on instrumentality. The passage begins by identifying Assyria as God’s instrument and ends by rebuking Assyria for forgetting that it is an instrument. Concurrence is not an interpretive overlay; it is the structural logic of the oracle itself.
Systematic Theology
“The almighty power, unsearchable wisdom, and infinite goodness of God so far manifest themselves in his providence that it extendeth itself even to the first fall, and all other sins of angels and men, and that not by a bare permission, but such as hath joined with it a most wise and powerful bounding, and otherwise ordering and governing of them, in a manifold dispensation, to his own holy ends.”
— WCF 5.4 / 1689 LBCF 5.4 (citing Isa. 10:6–7, 12)The Westminster divines did not choose Isaiah 10 arbitrarily. They recognized that the text’s own structure—God sending the Assyrian for a specific purpose (v. 6), Assyria intending something different (v. 7), God finishing His own work through the invasion (v. 12), and then punishing the instrument (v. 12b)—is the biblical pattern that the doctrine of concurrence formalizes.
“The first cause is the prime mover in every action so that the second cause cannot move unless it is moved, nor act unless acted upon by the first. Otherwise it would be the principle of its own motion and so would no longer be the second cause, but the first.”
This is exactly the error Isaiah 10:15 rebukes. The Assyrian claimed to be the principle of his own motion: “By the strength of my hand I have done it” (v. 13). The text replies that this is as absurd as an axe claiming to chop without a woodsman.
God’s concurrence is “physical, immediate, and both previous and simultaneous.” The praecursus is “the action of God by which he, flowing into causes and their principles, excites and previously moves creatures to action and directs to the doing of a particular thing.” The concursus is God’s continued operation alongside the creature in the act itself.
God “posits [the secondary cause] and makes it move into action (praecursus) and further accompanies it in its working and leads it to its effect (concursus).”
Concurrence is “a special, physical, natural, immediate, and tangible operation by which He precedes the creature in every motion,” drawing from Acts 17:28: “in him we live and move and have our being.”
Answering the Objection
The charge of anachronism confuses naming a reality with creating it. Isaiah did not use the Latin term concursus. Neither did he use “monotheism,” “aseity,” or “covenant theology”—yet no one denies these realities are present in his writings. The question is not whether Isaiah employed later vocabulary but whether the conceptual content is present in his text. Consider what the text actually asserts:
God is the active agent who sends and commissions Assyria (v. 6)—first-cause agency.
Assyria acts according to its own sinful intentions (v. 7)—secondary-cause agency.
Both agencies operate simultaneously in the same event—concurrence.
God’s agency does not excuse Assyria’s guilt (vv. 5, 12)—moral accountability of the secondary cause.
Assyria’s agency does not diminish God’s sovereignty (v. 15)—primacy of the first cause.
These five propositions are the substance of the doctrine of concurrence. They are not imported into the text; they are stated by the text. The later Reformed tradition did not invent these truths; it organized and defended what Scripture had already revealed.
“God wisely and purposefully accomplishes His sovereign decree through… the daily endeavors of finite, morally responsible, decision-making, sinful people (see, for example, Isa. 10:5–19, especially vv. 6–7).”
The same objection, if applied consistently, would strip every doctrinal affirmation from its biblical foundations. The doctrine of the Trinity was formulated at Nicaea, but no one claims it is absent from Matthew 28:19. The doctrine of justification by faith alone was articulated at the Reformation, but no one claims Paul’s letters are silent on the matter. In the case of Isaiah 10, the fit between text and doctrine is as tight as an axe-head on its handle.
“Providence is the measure which God uses in directing things to their proper ends… divine providence includes not only the knowledge of God’s mind but also his will and election by which it is fixed and determined that events will happen in one way rather than another.”
Answering the Objection
The objection that Isaiah 10 “only shows Assyria disobeying God”—acting sinfully on its own, with God as a disapproving bystander—cannot account for the passage’s most basic features.
First: If Assyria was merely disobeying, why does God call Assyria “My rod” and “My staff”? One does not claim ownership of unauthorized actions. God does not call the golden calf “My calf” or Jeroboam’s altars “My altars.”
Second: If Assyria was merely disobeying, why does God say “I send him” and “I command him”? Disobedience presupposes a command that is violated. But in verse 6, God’s command is precisely what Assyria carries out. The Assyrian does not disobey the commission; he fulfills it. His sin lies in the manner, motive, and self-exaltation with which he acts—and in his attempt to go beyond what God purposed (v. 7).
Third: If Assyria was merely disobeying, why does verse 12 call the invasion God’s “work”? An event that God merely permits is not called God’s “work.”
Fourth: If Assyria was merely disobeying, the analogy of verse 15 has no basis. The entire rhetorical force depends on the premise that God was actively wielding the instrument. If Assyria was acting independently, then it would not be absurd for the axe to boast—because the axe really would have been chopping on its own.
“We read the Scriptures in vain if we fail to discover that the actions of men, evil men as well as good, are governed by the Lord God.”
If any creature were genuinely independent in its actions—if there were, as Sproul memorably put it, “one single molecule in this universe running around loose, totally free of God’s sovereignty”—then God’s promises could not be guaranteed. Isaiah 10 leaves no room for such a loose molecule.
The Solution
How can God send Assyria, call the invasion His work, and then justly punish Assyria for what it did? The Reformed tradition answers with the materia/forma distinction: God concurs with the physical entity (materia) of the act—the invasion itself, the movements of armies, the fall of cities—while the moral defect (forma)—the pride, cruelty, self-exaltation—proceeds entirely from the creature’s corrupt nature.
This is not a scholastic contrivance but a direct reading of the text. Verses 5–6 establish God’s governance of the act. Verses 7–14 reveal Assyria’s corrupt moral character. God is responsible for the event; Assyria is responsible for the arrogance, cruelty, and godlessness with which it acted.
“Though every action, whether good or bad, receives its specification from the working of providence—and to that is their existence in their several kinds to be ascribed—yet an evil action, in the evilness of it, depends not upon divine concourse and influence.”
“A man may play upon a jarring instrument, but the jarring is from itself.”
“God’s operative permission is that by which he only permitteth one and the same work to be done of others as it is evil, but as it is good he effectually worketh the same.”
Note that Perkins uses “permission”—but this is not bare permission. It is “operative permission,” charged with divine governance. The WCF 5.4 likewise insists the providence over sin is “not by a bare permission, but such as hath joined with it a most wise and powerful bounding, and otherwise ordering and governing of them.” The distinction between “bare” and “operative” permission is precisely the distance between the Arminian and the Reformed reading of Isaiah 10.
“The divine concursus energizes man and determines him efficaciously to the specific act, but it is man who gives the act its formal quality, and who is therefore responsible for its sinful character.”
Conclusion
The doctrine of concurrence does not hover above Isaiah 10 as an alien imposition. It is woven into the passage’s grammar (first-person possessive constructions, active Pi’el verbs), its imagery (rod, staff, axe, saw—all instruments requiring a wielder), its narrative logic (God sends, Assyria invades, God calls it His work, God punishes the instrument), and its theological architecture (dual intention, dual agency, single event). The passage does not merely permit a concurrence reading; it demands one.
“It is the merest trifling to substitute a bare permission for the providence of God, as if he sat in a watch-tower waiting for fortuitous events, his judgments meanwhile depending on the will of man.”
The God of Isaiah 10 does not sit in a watch-tower. He picks up the rod, aims the stroke, accomplishes His work, and then breaks the instrument for its insolence. The secondary cause is real—Assyria genuinely acts, genuinely intends, and genuinely sins. But it acts within the efficacious governance of the first cause.
God supplies Assyria with “all power to act, all fitness for it, and efficacy in it, as the axe has from the person that makes and uses it.”
The rod cannot wield itself. The axe cannot boast against the one who hews with it. And the bare permission thesis cannot survive the text that refutes it in every clause.
Isaiah 10 does not merely support the doctrine of concurrence. It is one of the doctrine’s deepest roots in the soil of Holy Scripture—planted there not by the hand of later systematicians, but by the God who wields nations as a man wields wood.