Revelation 17:9

(This requires a mind that has wisdom.) The seven heads are seven mountains the woman sits on. They are also seven kings:

Revelation 13:18

This calls for wisdom: Let the one who has insight calculate the beast's number, for it is man's number, and his number is 666.

Revelation 17:3

So he carried me away in the Spirit to a wilderness, and there I saw a woman sitting on a scarlet beast that was full of blasphemous names and had seven heads and ten horns.

Daniel 12:4

"But you, Daniel, close up these words and seal the book until the time of the end. Many will dash about, and knowledge will increase."

Daniel 12:8-10

I heard, but I did not understand. So I said, "Sir, what will happen after these things?"

Hosea 14:9

Who is wise? Let him discern these things! Who is discerning? Let him understand them! For the ways of the Lord are right; the godly walk in them, but in them the rebellious stumble.

Matthew 13:11

He replied, "You have been given the opportunity to know the secrets of the kingdom of heaven, but they have not.

Matthew 24:15

"So when you see the abomination of desolation -- spoken about by Daniel the prophet -- standing in the holy place (let the reader understand),

Revelation 13:1

Then I saw a beast coming up out of the sea. It had ten horns and seven heads, and on its horns were ten diadem crowns, and on its heads a blasphemous name.

Revelation 17:7

But the angel said to me, "Why are you astounded? I will interpret for you the mystery of the woman and of the beast with the seven heads and ten horns that carries her.

Revelation 17:18

As for the woman you saw, she is the great city that has sovereignty 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
This calls for wisdom: Let the one who has insight calculate the beast's number, for it is man's number, and his number is 666.
Daniel 12:4
"But you, Daniel, close up these words and seal the book until the time of the end. Many will dash about, and knowledge will increase."
Hosea 14:9
Who is wise? Let him discern these things! Who is discerning? Let him understand them! For the ways of the Lord are right; the godly walk in them, but in them the rebellious stumble.
Matthew 13:11
He replied, "You have been given the opportunity to know the secrets of the kingdom of heaven, but they have not.
Matthew 24:15
"So when you see the abomination of desolation -- spoken about by Daniel the prophet -- standing in the holy place (let the reader understand),

The seven

Revelation 17:3
So he carried me away in the Spirit to a wilderness, and there I saw a woman sitting on a scarlet beast that was full of blasphemous names and had seven heads and ten horns.
Revelation 13:1
Then I saw a beast coming up out of the sea. It had ten horns and seven heads, and on its horns were ten diadem crowns, and on its heads a blasphemous name.

NET Bible copyright © 1996-2006 by Biblical Studies Press, L.L.C. NetBible