Romans 3:13 Commentary: Speech as an Open Tomb and Viper's Poison

Romans 3:13 is part of a catena, a chain of Old Testament quotations, that Paul assembles from verses 10 to 18. He draws mainly from the Psalms (14, 5, 140, 10, 36) and Isaiah 59. The immediate context is Romans 3:9, 20, where Paul concludes his argument that both Jews and Greeks are "all under sin" (v.9). Having shown the moral failure of Gentiles in chapter 1 and of Jews in chapter 2, he now weaves together Scripture passages that catalog human wickedness.

The first metaphor, "their throat is an open tomb," comes from Psalm 5:9, a psalm of David against his enemies. In the original Hebrew, the line emphasizes the throat as a place of destruction, perhaps linked to the way a grave devours bodies. The Greek Septuagint uses τάφος ἀνεῳγμένος, a standing-open grave. Ancient Jewish exegesis often associated such imagery with insatiable greed or speech that corrupts. The second metaphor, "the poison of vipers is under their lips," is from Psalm 140:3, where the psalmist prays for deliverance from slanderous men whose words are like serpent venom. The asp (ἀσπίς) was known for its small size and instantaneous, deadly bite (Barnes).

Paul's choice to quote the Septuagint rather than the Hebrew suggests his audience included Greek-speaking Jews and Gentiles. Placing these verses in a catena emphasizes that the problem is not merely individual sins but a systemic corruption that infects every part of a person, from throat to lips. The rhetorical aim is to "stop every mouth" (v.19) and leave no room for self-justification. The open grave and snake venom are not just vivid images; they convey the lethality and hiddenness of sin in speech.

The supplied commentators note that the words of Romans 3:13 exist in the Septuagint but not in the Hebrew text of the Psalms at these exact points. Clarke observes that the most ancient copies of the Septuagint do not contain these verses, leading some to argue that later transcribers interpolated them from Paul's letter. However, the majority view holds that Paul was quoting a version of the Septuagint current in his day, and the textual basis is secure.

Romans 3:13 has been cited throughout church history to support the doctrine of original sin and the corruption of human nature. Early church fathers used it in debates against Pelagius to show that sin affects even speech from infancy. The verse appears in creeds and confessions, such as the Canons of Dort, as evidence that all people are morally unable to speak good apart from grace. In the medieval period, it was used in penitential literature to warn against sins of the tongue. Reformers like Calvin quoted the verse in their commentaries to emphasize the depth of human depravity and the need for divine regeneration of the heart. Modern treatments continue to apply the imagery to the power of words in community life.

Three-point outline

1. The open grave. The throat is likened to a tomb standing open. This suggests either a pit that swallows up others (devouring greed or slander) or a source of decaying air that poisons everything around. Both interpretations point to the destructive power of words.
2. Deceitful tongues. The imperfect tense of εδολιοῦσαν ("they were practicing deceit") shows habitual, persistent falsehood. Flattery, lies, and broken promises are not occasional slips but patterns of the fallen heart.
3. Hidden poison. Venom lies under the lips, concealed until the moment of wounding. This captures the stealth of slander: seemingly harmless words carry deadly intent. Like the asp's bite, the damage is rapid and often irreversible.

Five-point outline

1. The throat as an open tomb: devouring or corrupting.
2. The tongue used for deceit: habitual hypocrisy.
3. The poison of asps under lips: hidden slander.
4. The mouth full of cursing and bitterness (v.14).
5. The feet swift to shed blood (v.15).

Illustration hooks

• An open grave on a pathway: unseen, sudden fall, no escape. Our words can create traps for others.
• A rattlesnake coiled near a hiking trail: quiet, camouflaged, but lethal. Gossip and slander often hide beneath a harmless exterior.
• A rumor that spreads through a church like a virus: once spoken, it cannot be retrieved, and it poisons relationships for years.

Questions your congregation is asking

• How can I control my tongue when I feel angry or hurt?
• Are there kinds of speech that seem small but are actually serious sins?
• Does this passage mean that all people are as bad as they could be, or that every part of us is affected by sin?

Paul's catena in Romans 3:10-18 paints a bleak picture of humanity. Verse 13 focuses on the organs of speech, throat, tongue, lips, and uses shocking imagery to show that our words are not neutral. As a group, explore what this verse reveals about sin and how it calls us to honesty about our own hearts.

Discussion questions

1. Read Romans 3:9-20 aloud. How does verse 13 fit into Paul's larger argument about Jews and Gentiles?
2. The phrase "open tomb" could mean a grave that devours or one that emits foul air. Which interpretation do you think fits the context better? Why?
3. What does the imperfect tense of εδολιοῦσαν ("they were practicing deceit") tell us about the nature of sinful speech? Is it occasional or habitual?
4. Why do you think Paul uses the image of a snake's poison hidden under the lips? What does this suggest about the source of slander?
5. How does this passage challenge the common idea that "sticks and stones may break my bones, but words will never hurt me"?
6. In what ways do we see the same patterns of speech in our own culture, on social media, in politics, or even among Christians?
7. What hope does Paul offer later in Romans for people whose speech is so corrupted? (Look ahead to Romans 6:17-18 or 12:14.)