In 2 Timothy 3:8, the reference to Jannes and Jambres provides the background for the statement about their folly being plain in verse 9.

Exodus 8:18 records the magicians' inability to produce gnats — a key example of their folly being exposed, as Paul references.

Exodus 8:19 has the magicians confessing 'This is the finger of God' — their failure made plain, matching Paul's point about folly.

Exodus 9:11 describes the magicians unable to stand because of boils — another demonstration of their folly, as Paul alludes.

Exodus 7:12 shows the magicians' staffs being swallowed by Aaron's — the very failure Paul says will be plain for false teachers.

Jeremiah 28:15-17 records Hananiah's false prophecy and his death — a clear OT example of a false prophet's folly exposed.

Jeremiah 29:21-23 tells of false prophets Ahab and Zedekiah being killed by Nebuchadnezzar — their lies exposed.

Jeremiah 29:32 pronounces punishment on Shemaiah — his folly leads to consequences, making his deception plain.

Jeremiah 37:19 asks where the false prophets are now — their failed predictions are evident, exposing their folly.

Acts 19:15-17 describes the sons of Sceva overpowered — this becomes known to all, exposing their presumption and folly.

Acts 13:11 shows Elymas struck blind — his opposition is exposed and the proconsul believes. Folly made plain.

In 1 John 2:19, the same idea of exposure: false believers 'went out' to become plain that they were not of us — directly parallels the folly being made plain.

Luke 20:26 shows opponents silenced and unable to trap Jesus — their failed scheme parallels false teachers whose folly becomes evident.

Micah 3:7 says seers will be disgraced and put to shame — directly matching Paul's point that false teachers' folly will be clear.

Daniel 4:7 shows magicians unable to interpret the king's dream — their failure exposes their folly, just as Paul describes.

Ezekiel 13:23 declares false visions will cease and God will deliver His people — directly echoing that false teachers will not get far.

1 Kings 18:29 shows Baal's prophets failing all day — their powerless prophecy is exposed as folly on Carmel.

Ezekiel 13:3 pronounces woe on foolish prophets who follow their own spirit — the same folly Paul says will be exposed.

Luke 13:17 describes Jesus' adversaries being put to shame — a parallel to false teachers whose folly is openly exposed.

In 1 Corinthians 3:13, the same theme of exposure: the Day will make each person's work manifest, just as the false teachers' folly will be plain.