Revelations 13: 11-18

11. And I beheld another beast rising out of the earth;
it had two horns like a lamb, and spoke as a dragon.

12. And he exercises all the power of the first beast before him,
and causes the earth and them which dwell therein to worship the first beast,
whose deadly wound was healed.

13. And he did great wonders, even making fire come down from heaven to earth in the sight of all,

14. By the wonders it had power to do in behalf of the beast,
it deceived the inhabitants of the earth,
telling them to make an image to the beast,
which had the wound by a sword, and yet lived.

15. And it had power to give breath to the image of the beast,
that the image of the beast should both speak,
and cause those who would not worship the image of the beast to be killed.

16. And it caused all, both small and great, rich and poor, free and slave,
to receive a mark in their right hand, or in their foreheads:

17. That none could buy or sell, who did not have the mark:
the name of the beast, or the number of his name.

18. Here is wisdom. Let him that hath understanding calculate the number of the beast:
for it is the number of a man; and his number is Six hundred threescore and six.