1 Corinthians 5:2 reveals the specific pride Paul rebukes — being proud instead of mourning over sin — which he calls 'not good' here.

1 Corinthians 5:8 directly applies the leaven metaphor, defining it as malice and evil and calling for purity.

1 Corinthians 4:18 mentions the same arrogance: some were 'puffed up' as if Paul weren't coming, reinforcing the rebuke of boasting.

1 Corinthians 4:19 continues the thought: Paul will come to test the power behind their arrogant talk, linking to the empty boasting here.

1 Corinthians 3:16 reminds them they are God's temple, adding urgency to the need to purge the leaven of sin.

1 Corinthians 3:21 also condemns boasting — there about human leaders — showing a consistent theme of pride in this church.

1 Corinthians 15:33 warns that 'bad company corrupts good character' — the same principle underlying the leaven metaphor about sin's spread.

Matthew 13:33 uses yeast to picture the kingdom's spread — the opposite meaning from Paul's use of yeast for sin's spread here.

Matthew 16:6-12 uses 'yeast of the Pharisees' as corrupting teaching — the same metaphor as Paul's for corrupting sin.

Galatians 5:9 repeats the exact same proverb about leaven spreading — Paul uses it for false teaching, paralleling the corrupting influence here.

Hebrews 12:15 warns against a root of bitterness that defiles many — similar to how leaven spreads and corrupts the whole lump.

Mark 8:15 warns against the 'leaven of the Pharisees' — Jesus uses the same metaphor for corrupting influence, reinforcing Paul's usage.

2 Timothy 2:16 uses the image of gangrene spreading — like leaven, corrupting talk spreads and pollutes the whole community.

Leviticus 2:11 forbids leaven in grain offerings — reinforcing leaven as impurity, directly supporting Paul's metaphor.

Galatians 2:12 shows Peter's hypocrisy influencing other Jews, illustrating how a little compromise leavens the whole lump.

Luke 13:21 uses the same leaven metaphor for the kingdom's spread — here it warns of sin's spread instead.

Exodus 12:8 commands unleavened bread at Passover — the OT background for leaven symbolizing purity, which Paul applies to sin.

James 4:16 directly says 'all such boasting is evil' — a parallel NT condemnation of the same attitude Paul rebukes.

2 Timothy 2:17 uses gangrene spreading as a metaphor for false teaching — similar to leaven, but a different image of corruption.