1 Kings 8:46 declares that no one is without sin, directly supporting the rhetorical question about purity.

2 Chronicles 6:36 repeats the same admission of universal sin, reinforcing the impossibility of claiming purity.

Job 14:4 asks who can bring clean from unclean, affirming that no one can claim a pure heart.

Job 15:14 asks what man is that he should be clean, echoing the same theme of universal human impurity.

In Job 25:4, Bildad asks how a mortal can be pure before God — the same rhetorical challenge about claiming a clean heart.

Psalm 51:5 states that all are conceived in sin — the reason no one can claim to have made their heart clean.

Ecclesiastes 7:20 declares no one does good without sinning — confirming the impossibility of claiming purity.

James 3:2 says we all stumble in many ways — universal sinfulness prevents anyone from claiming a clean heart.

1 John 1:8-10 warns that claiming sinlessness is self-deception — a direct echo of Proverbs' rhetorical question.

Genesis 8:21 states man's heart is evil from youth — explaining why no one can claim to be pure.

Psalm 24:4 describes the ideal of clean hands and pure heart for worship — the standard Proverbs says no one can claim.

2 Corinthians 7:1 urges cleansing from defilement — a New Testament response to the admission in Proverbs 20:9 that no one can claim purity on their own.