Genesis 21:4

KJV

And Abraham circumcised his son Isaac being eight days old, as God had commanded him.

KJV (with Strong's)

And Abraham {H85} circumcised {H4135} his son {H1121} Isaac {H3327} being eight {H8083} days {H3117} old {H1121}, as God {H430} had commanded {H6680} him.

Complete Jewish Bible

Avraham circumcised his son Yitz'chak when he was eight days old, as God had ordered him to do.

Berean Standard Bible

When his son Isaac was eight days old, Abraham circumcised him, as God had commanded him.

American Standard Version

And Abraham circumcised his son Isaac when he was eight days old, as God had commanded him.

Commentary

### SUMMARY
Genesis 21:4 meticulously records Abraham's immediate and faithful obedience to God's specific command by circumcising his son Isaac when he was precisely eight days old. This pivotal act formally inducted Isaac, the long-awaited son of promise, into the Abrahamic covenant, thereby signifying his participation in God's unique relationship with Abraham's descendants and profoundly reaffirming both God's unwavering faithfulness in providing the promised heir and Abraham's profound trust in divine instruction.

### CONTEXT
* **Literary Context:** Genesis 21:4 is nestled within a momentous period in Abraham's life, immediately following the miraculous birth of Isaac to Abraham and Sarah in their old age, as detailed in [Genesis 21:1-3](/genesis/21-1-3 "The Birth and Naming of Isaac"). The preceding chapters have meticulously built up to this fulfillment of God's long-standing promise, first given in [Genesis 15](/genesis/15 "God's Covenant with Abram") and reiterated with increasing specificity, including the promise of a son through Sarah and the institution of circumcision as a covenant sign in [Genesis 17](/genesis/17 "The Covenant of Circumcision"). The naming of Isaac, meaning "he laughs," in [Genesis 21:3](/genesis/21-3 "Isaac's birth and naming") sets the stage for this act of covenantal inclusion, emphasizing the joy and divine origin of this child. Thus, the circumcision of Isaac is not an isolated event but the crucial next step in the unfolding narrative of God's covenant faithfulness and Abraham's obedient response, formally integrating the heir into the lineage of promise.
* **Historical & Cultural Context:** Circumcision was practiced by various ancient Near Eastern peoples, but for Israel, it carried a unique theological significance. Unlike surrounding cultures where it might have been a rite of passage, a hygienic practice, or a tribal mark, for Abraham and his descendants, it was explicitly commanded by God as the physical sign of the [Abrahamic covenant](/genesis/17-9-14 "The Covenant of Circumcision Established") ([Genesis 17:10-14](/genesis/17-10-14 "God's Command for Circumcision")). This made it a religious obligation, distinguishing God's chosen people. The specific timing of the eighth day, later codified in Mosaic Law ([Leviticus 12:3](/leviticus/12-3 "Law concerning Circumcision after Childbirth")), was unique and held profound implications, both theological and, as modern science has revealed, medical. Abraham's adherence to this precise timing demonstrates his commitment to God's specific, rather than general, commands, setting a precedent for the covenant community.
* **Key Themes:** This verse powerfully contributes to several overarching themes within Genesis and the broader biblical narrative. Foremost is the theme of **Divine Faithfulness and Promise-Keeping**, as Isaac's birth and subsequent covenantal inclusion are direct fulfillments of God's miraculous promises to Abraham and Sarah, even in their old age ([Genesis 18:10-14](/genesis/18-10-14 "The Lord's Promise to Abraham and Sarah")). Closely related is the theme of **Human Obedience and Faith**, exemplified by Abraham's prompt and precise execution of God's command, which serves as a model of [faith demonstrated through action](/hebrews/11-8 "Abraham's Obedience by Faith"). The act of circumcision itself underscores the theme of **Covenant and Election**, marking Isaac as a participant in God's special relationship with Abraham's lineage and signifying the distinct identity and responsibilities of God's chosen people. Finally, the specific detail of the "eight days old" subtly introduces the theme of **Divine Wisdom in Law**, hinting at a perfect design in God's commands that transcends immediate human understanding.

### EXPOSITION AND ANALYSIS
Genesis 21:4 succinctly captures a moment of profound theological significance, demonstrating Abraham's unwavering obedience and the formal inclusion of Isaac into God's covenant.

#### Key Word Analysis
* **Circumcised (Hebrew, _mûwl'_):** From a primitive root meaning "to cut short," specifically referring to the foreskin. In this context, it denotes the ritual act commanded by God as the sign of the Abrahamic covenant. It implies not just the physical act but the spiritual significance of setting apart and dedicating to God, a cutting away that marks belonging and identity within the covenant community.
* **Isaac (Hebrew, _Yitschâq'_):** Derived from the Hebrew root meaning "laughter." This name was given by divine instruction ([Genesis 17:19](/genesis/17-19 "God's Promise of Isaac's Name")) and reflects the reaction of both Abraham and Sarah to the seemingly impossible promise of his birth ([Genesis 17:17](/genesis/17-17 "Abraham's Laughter") and [Genesis 18:12](/genesis/18-12 "Sarah's Laughter")). His naming and subsequent circumcision underscore his identity as the miraculous "son of promise," the one through whom God's covenant with Abraham would continue.
* **Commanded (Hebrew, _tsâvâh'_):** An intensive primitive root meaning "to constitute, enjoin." This word highlights the authoritative nature of God's instruction to Abraham regarding circumcision ([Genesis 17:9-14](/genesis/17-9-14 "God's Command for Circumcision")). It emphasizes that Abraham's action was not a personal choice or cultural custom but a direct, divine mandate, making his obedience a direct response to God's sovereign will.

#### Verse Breakdown
* **"And Abraham circumcised his son Isaac":** This clause directly attributes the action to Abraham, emphasizing his personal responsibility and active role in fulfilling God's command. The mention of "his son Isaac" immediately identifies the subject of the covenant act as the long-awaited heir, the fulfillment of God's promise, and the one through whom the covenant lineage would continue.
* **"being eight days old":** This precise detail is crucial. It highlights Abraham's strict adherence to the exact timing stipulated by God in [Genesis 17:12](/genesis/17-12 "Command for Circumcision on the Eighth Day"). This specific timing was not arbitrary; it would later be codified in Mosaic Law and, remarkably, aligns with modern medical understanding regarding a newborn's clotting factors being optimal around the eighth day, minimizing the risk of hemorrhage. This subtle detail underscores God's perfect wisdom in His commands, even in seemingly ritualistic stipulations.
* **"as God had commanded him":** This concluding phrase is central to the verse's meaning. It explicitly links Abraham's action directly to divine instruction, serving as the theological justification for the act. It underscores Abraham's unwavering obedience to God's specific instructions, reinforcing his character as a man of profound faith. This obedience was not merely an act of compliance but a demonstration of trust in the God who had promised and now delivered the son.

#### Literary Devices
The verse employs several literary devices to convey its profound meaning. **Conciseness** is evident in its brief yet impactful statement, packing significant theological weight into a few words. The phrase "as God had commanded him" functions as a form of **Attribution** or **Justification**, explicitly linking Abraham's action to divine authority and underscoring the theme of obedience. The precise detail "eight days old" serves as **Emphasis** on Abraham's meticulous adherence to God's instructions, highlighting his faithfulness. Furthermore, the act of circumcision itself is rich in **Symbolism**, representing the physical mark of the covenant, the setting apart of God's chosen people, and a foreshadowing of the spiritual cutting away of sin. The narrative implicitly uses **Foreshadowing** by highlighting God's wisdom in the timing, which would later be understood medically, hinting at the divine design embedded within God's commands.

### THEOLOGICAL AND THEMATIC CONNECTIONS
Genesis 21:4 stands as a testament to God's covenant faithfulness and Abraham's obedient response, weaving together foundational theological principles that resonate throughout biblical history. The physical act of circumcision, precisely executed, served as the visible sign of an invisible spiritual reality: God's election of Abraham's lineage and their participation in His redemptive plan. This event reinforces the truth that God's promises are sure, and His commands are to be obeyed with trust and precision, establishing the pattern for the covenant community.

* [Genesis 17:9-14](/genesis/17-9-14 "God's Command for Circumcision"): Abraham's prompt and precise adherence to the instruction regarding circumcision underscores the critical importance of obedience as the proper human response to God's covenant faithfulness and authority.
* [Genesis 17:10-14](/genesis/17-10-14 "The Covenant of Circumcision"): Isaac's circumcision signifies his immediate inclusion in the Abrahamic covenant, highlighting the concept of inherited covenantal blessings and responsibilities, marking him as belonging to God's chosen people.
* [Genesis 18:10-14](/genesis/18-10-14 "The Promise of Isaac's Birth"): The very existence of Isaac, and his subsequent circumcision, is a powerful testament to God's unwavering faithfulness in fulfilling His promises, even when human circumstances seem to make them impossible.

### REFLECTION AND APPLICATION
Abraham's example in [Genesis 21:4](/genesis/21-4 "Abraham Circumcises Isaac") offers profound and enduring lessons for believers today. It calls us to consider the depth of our own obedience to God's Word, reminding us that true faith is not merely intellectual assent but is demonstrated through our willingness to follow His commands precisely and promptly, even when they may seem counter-cultural or challenging. Just as physical circumcision marked a covenant relationship in the Old Testament, Christians are called to a "circumcision of the heart," a spiritual transformation that involves a radical cutting away of sin and a complete dedication to Christ. This spiritual reality, described in the New Testament, signifies a new identity and belonging in God's family, not through external ritual but internal renewal. For parents, this verse highlights the sacred responsibility to nurture their children in faith, introducing them to God's covenant relationship from an early age and modeling a life of devoted obedience to divine commands. Our lives, like Abraham's, should bear witness to our trust in God's perfect wisdom and unwavering faithfulness.

#### Questions for Reflection
* **In what areas of your life is God calling you to a deeper, more precise obedience, even when His commands seem counter-intuitive?**
* **How does the concept of "circumcision of the heart" apply to your daily walk with Christ, and what "cutting away" might God be asking of you?**
* **As a parent or spiritual mentor, how can you better model and teach faithful obedience to God's commands to those under your influence?**

### FAQ
**Why was circumcision performed on the eighth day?**

Answer: The Old Testament law, as established in [Genesis 17:12](/genesis/17-12 "Command for Circumcision on the Eighth Day") and later codified in [Leviticus 12:3](/leviticus/12-3 "Law concerning Circumcision after Childbirth"), specified the eighth day for circumcision. This timing is not arbitrary; modern medical science confirms that a newborn's vitamin K levels, crucial for blood clotting, are at their peak around the eighth day, minimizing the risk of hemorrhage. This detail highlights God's perfect wisdom in His commands, demonstrating a divine foresight that predates human medical understanding and underscores the benevolent nature of His laws.

**Is physical circumcision still a requirement for believers today?**

Answer: No. The New Testament clarifies that physical circumcision is not a requirement for salvation or inclusion in the New Covenant. The Jerusalem Council in [Acts 15](/acts/15 "The Jerusalem Council on Circumcision") decisively addressed this, concluding that Gentile believers were not required to be circumcised. Paul further emphasizes in [Galatians 5:6](/galatians/5-6 "Faith Working Through Love") that "neither circumcision nor uncircumcision has any value—only faith working through love." Instead, believers are called to a "circumcision of the heart" ([Romans 2:29](/romans/2-29 "Circumcision of the Heart")), a spiritual transformation marked by repentance, faith, and obedience to Christ, signifying a cutting away of sin and a new identity in Him ([Colossians 2:11](/colossians/2-11 "Circumcision of Christ")).

### CHRIST-CENTERED FULFILLMENT
The circumcision of Isaac, the son of promise, finds its ultimate fulfillment and deeper meaning in the person and work of Jesus Christ. Isaac's miraculous birth, a testament to God's power over human impossibility, foreshadows the even greater spiritual birth and new creation found in Christ. The physical sign of circumcision, marking one as belonging to Abraham's lineage and the Old Covenant, points forward to the spiritual "circumcision of the heart" accomplished through Jesus. In the New Covenant, true belonging to God's family is not through physical lineage or ritual but through faith in Jesus, who perfectly fulfilled the law and established a new covenant by His blood. Christ Himself is the ultimate "Son of promise," the seed of Abraham through whom all the blessings promised to Abraham are extended to all nations ([Galatians 3:16](/galatians/3-16 "The Promise to Abraham and His Seed")). Through His death and resurrection, believers are spiritually circumcised, having their old sinful nature "cut away" and being made new in Him ([Colossians 2:11-12](/colossians/2-11-12 "Circumcision of Christ and Baptism")). Thus, the obedience of Abraham in circumcising Isaac points to the greater obedience of Christ, whose perfect life and sacrificial death provide the means for all who believe to be truly set apart for God, not by a physical mark, but by spiritual transformation and union with Him ([Romans 2:28-29](/romans/2-28-29 "True Circumcision is of the Heart")).

Note: Commentary is generated by AI with a directive for Biblical fidelity. Always rely on the Holy Spirit for discernment. The Scripture text and cross-references are from verified, non-AI sources.

Cross-References

Acts 7:8

And he gave him the covenant of circumcision: and so [Abraham] begat Isaac, and circumcised him the eighth day; and Isaac [begat] Jacob; and Jacob [begat] the twelve patriarchs.

Genesis 17:10

This [is] my covenant, which ye shall keep, between me and you and thy seed after thee; Every man child among you shall be circumcised.

Genesis 17:12

And he that is eight days old shall be circumcised among you, every man child in your generations, he that is born in the house, or bought with money of any stranger, which [is] not of thy seed.

Luke 2:21

¶ And when eight days were accomplished for the circumcising of the child, his name was called JESUS, which was so named of the angel before he was conceived in the womb.

Exodus 12:48

And when a stranger shall sojourn with thee, and will keep the passover to the LORD, let all his males be circumcised, and then let him come near and keep it; and he shall be as one that is born in the land: for no uncircumcised person shall eat thereof.

Leviticus 12:3

And in the eighth day the flesh of his foreskin shall be circumcised.

Luke 1:59

And it came to pass, that on the eighth day they came to circumcise the child; and they called him Zacharias, after the name of his father.