2 Peter 2:6

and reducing the cities of Sodom and Gomorrha to ashes, condemned them to destruction, making them an example to those that should afterwards be impious;

1 Corinthians 10:6-10

Now these things were examples for us, that we might not lust after evil things, as they also lusted.

Jude 1:7

as Sodom and Gomorrha, and the cities about them, in like manner with them committing lewdness, and going after strange flesh, are set forth as an example, suffering the vengeance of perpetual fire.

Treasury of Scripture Knowledge

Summary

And the earth opened her mouth, and swallowed them up together with Korah, when that company died, what time the fire devoured two hundred and fifty men: and they became a sign.

Bible References

They became a sign

1 Corinthians 10:6
Now these things were examples for us, that we might not lust after evil things, as they also lusted.
2 Peter 2:6
and reducing the cities of Sodom and Gomorrha to ashes, condemned them to destruction, making them an example to those that should afterwards be impious;
Jude 1:7
as Sodom and Gomorrha, and the cities about them, in like manner with them committing lewdness, and going after strange flesh, are set forth as an example, suffering the vengeance of perpetual fire.