Revelation 17:9

Now for the interpretation of the discerning mind! The seven heads are seven hills, on which the woman is seated:

Revelation 13:18

Now for the gift of interpretation! Let the discerning calculate the cipher of the Beast; it is the cipher of a man, and the figures are six hundred and sixty-six.

Revelation 17:3

So he bore me away rapt in the Spirit to the desert, and I saw a woman sitting on a scarlet Beast covered with blasphemous titles; it had seven heads and ten horns.

Matthew 13:11

He replied, "Because it is granted you to understand the open secrets of the Realm of heaven, but it is not granted to these people.

Matthew 24:15

So when you see the appalling Horror spoken of by the prophet Daniel, standing erect in the holy place (let the reader note this),

Revelation 13:1

Then I stood on the sand of the sea, and I saw a Beast rising out of the sea with ten horns and seven heads, ten diadems on his horns, and blasphemous titles on his heads.

Revelation 17:7

But the angel said to me, "Why marvel? I will explain to you the mystery of the woman, and of the Beast with the seven heads and the ten horns who carries her.

Revelation 17:18

As for the woman you have seen, she is the great City which reigns 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
Now for the gift of interpretation! Let the discerning calculate the cipher of the Beast; it is the cipher of a man, and the figures are six hundred and sixty-six.
Matthew 13:11
He replied, "Because it is granted you to understand the open secrets of the Realm of heaven, but it is not granted to these people.
Matthew 24:15
So when you see the appalling Horror spoken of by the prophet Daniel, standing erect in the holy place (let the reader note this),

The seven

Revelation 17:3
So he bore me away rapt in the Spirit to the desert, and I saw a woman sitting on a scarlet Beast covered with blasphemous titles; it had seven heads and ten horns.
Revelation 13:1
Then I stood on the sand of the sea, and I saw a Beast rising out of the sea with ten horns and seven heads, ten diadems on his horns, and blasphemous titles on his heads.