2 Peter 2:6

And turning the cities of Sodom and Gomorrah into ashes, condemned them with an overthrow, making them an example to them that should afterwards live ungodly:

1 Corinthians 10:6-10

Now these things were for our example, that we might not desire evil things, as they desired.

Jude 1:7

Even as Sodom and Gomorrah and the cities about them, which in the same manner with these gave themselves over to fornication, and went after strange flesh, are set forth for an example, suffering the vengeance of eternal 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 for our example, that we might not desire evil things, as they desired.
2 Peter 2:6
And turning the cities of Sodom and Gomorrah into ashes, condemned them with an overthrow, making them an example to them that should afterwards live ungodly:
Jude 1:7
Even as Sodom and Gomorrah and the cities about them, which in the same manner with these gave themselves over to fornication, and went after strange flesh, are set forth for an example, suffering the vengeance of eternal fire.