Revelation 13:16
And 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,
What it says
The second beast requires all people to receive a mark on hand or forehead.
What it is doing
This verse introduces the public sign of beastly allegiance.
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.