Revelation 13:18
Here is a call for wisdom: Let the one who has insight calculate the number of the beast, for it is the number of a man, and that number is 666.
What it says
Wisdom is needed to calculate the beast's number, which is 666.
What it is doing
This verse closes the chapter by summoning discerning resistance to the beast's system.
In context
16And the second beast required all people, small and great, rich and poor, free and slave, to receive a mark on their right hand or on their forehead, 17so that no one could buy or sell unless he had the mark — the name of the beast or the number of its name. 18Here is a call for wisdom: Let the one who has insight calculate the number of the beast, for it is the number of a man, and that number is 666.