Why is Onan Important?
Then Judah said to Onan, "Go in to your brother's wife and perform the duty of a brother-in-law to her, and raise up offspring for your brother." But Onan knew that the offspring would not be his. So whenever he went in to his brother's wife he would waste the semen on the ground, so as not to give offspring to his brother. And what he did was wicked in the sight of the Lord, and he put him to death also.
Key Facts
Term Name
Onan
Role
Brother of Er and brother-in-law to Tamar
Born
c. 1900 BC
Died
c. 1900 BC
Key Takeaways
- Onan failed to fulfill his levirate duty, leading to divine judgment.
- God’s judgment on Onan highlights the seriousness of ethical choices.
- Onan’s omission from Jesus’ genealogy underscores the value of faithfulness over lineage.
Who Was Onan in the Bible?
Onan, the son of Judah and brother of Er, became Tamar’s brother-in-law after Er’s death, setting the stage for the events in Genesis 38:8-10.
Genesis 38:8-10 explains that Onan was obligated to marry his brother’s widow, Tamar, to provide an heir for Er. However, he deliberately avoided fulfilling this duty by spilling his semen on the ground, prompting God to take his life for his disobedience.
Onan's Sin and Its Consequences
Genesis 38:8-10 recounts Onan’s deliberate disobedience to his levirate duty and the divine judgment that followed.
Judah instructed Onan to marry his brother Er’s widow, Tamar, to provide an heir for Er (Genesis 38:8). However, Onan intentionally avoided fulfilling this responsibility by spilling his semen on the ground during their intimate union, ensuring Tamar would not conceive (Genesis 38:9). As a result, the Lord struck Onan dead for his wickedness, declaring his actions ‘wicked in the Lord’s sight’ (Genesis 38:10).
The Legacy of Onan in Scripture
Onan's name serves as a cautionary example in biblical genealogies, illustrating consequences for moral failure.
In Matthew 1:1-17, Onan is omitted from Jesus' genealogy, signaling his disqualification from the line of kingship due to his disobedience (Genesis 38:10). This omission underscores the biblical theme that faithfulness, not lineage alone, determines one's role in God's redemptive plan.
What We Can Learn From Onan’s Story
Onan’s brief narrative underscores the weight of ethical responsibility and the consequences of willful disobedience.
His deliberate refusal to fulfill his levirate duty (Genesis 38:9)—spilling his semen on the ground to avoid giving Tamar an heir—reveals a failure to honor both his family and God’s design for life. By prioritizing self-interest over duty, Onan demonstrated a lack of integrity, and God judged his actions as ‘wicked in the Lord’s sight’ (Genesis 38:10). This highlights how ethical choices, even in private, carry spiritual significance.
The swift and severe judgment on Onan (Genesis 38:10) illustrates the gravity with which God views intentional sin. His story serves as a reminder that moral failure disrupts God’s purposes, even within familial and cultural obligations, and that faithfulness—not mere lineage—shapes one’s legacy (Matthew 1:1-17).
Further Reading
Key Scripture Mentions
Genesis 38:8-10
The account of Onan’s disobedience and God’s judgment.
Matthew 1:1-17
Jesus’ genealogy, omitting Onan due to his unfaithfulness.
Related Concepts
Levirate Marriage (Theological Concepts)
The biblical practice of marrying a brother’s widow to provide an heir.
Tamar (Figures)
Onan’s brother-in-law, central to the narrative of Genesis 38.
Judah (Figures)
Onan’s father, who oversaw the levirate obligation in Genesis 38.