Revelation 13:15-17

The beast from the earth was empowered to breathe life into the image of the first beast so that it could speak and kill those who refused to worship its image. It also caused everyone, small and great, rich and poor, free and bound, to be marked on the right hand or on the forehead. This meant no one could buy or sell unless they had the mark; that is, the name of the beast or its number.