Revelation 17:9

Here is scope for a mind that is packed with wisdom. The seven heads are the seven hills on which the woman is seated.

Revelation 13:18

Here is scope for wisdom! Let anyone who has the mental keenness calculate the number of the wild beast, for it is the number of a certain man; his number is six hundred and sixty-six.

Revelation 17:3

So he carried me away in spiritual rapture to a desert, and I saw a woman seated on a scarlet wild beast, covered with blasphemous titles; he had seven heads and ten horns.

Matthew 13:11

He answered: "It is you and not they who are granted the privilege of knowing the secrets of the kingdom of heaven.

Matthew 24:15

"So when you see the destructive desecration, mentioned by the prophet Daniel, standing in the Holy Place" -- let the reader take notice --

Revelation 13:1

Then I stood on the sand of the seashore, and I saw a wild beast coming up out of the sea with ten horns and seven heads, with ten diadems on his horns, and blasphemous titles on his heads.

Revelation 17:7

but the angel said to me: "Why are you astonished? I will tell you the symbolical meaning of the woman, and the wild beast with seven heads and ten horns, that carries her.

Revelation 17:18

And the woman whom you saw is the great city that has dominion over the kings of the earth."

Treasury of Scripture Knowledge

Summary

And here is the mind which hath wisdom. The seven heads are seven mountains, on which the woman sitteth.

Bible References

Here

Revelation 13:18
Here is scope for wisdom! Let anyone who has the mental keenness calculate the number of the wild beast, for it is the number of a certain man; his number is six hundred and sixty-six.
Matthew 13:11
He answered: "It is you and not they who are granted the privilege of knowing the secrets of the kingdom of heaven.
Matthew 24:15
"So when you see the destructive desecration, mentioned by the prophet Daniel, standing in the Holy Place" -- let the reader take notice --

The seven

Revelation 17:3
So he carried me away in spiritual rapture to a desert, and I saw a woman seated on a scarlet wild beast, covered with blasphemous titles; he had seven heads and ten horns.
Revelation 13:1
Then I stood on the sand of the seashore, and I saw a wild beast coming up out of the sea with ten horns and seven heads, with ten diadems on his horns, and blasphemous titles on his heads.