16 It also forced all people, great and small, rich and poor, free and slave, to receive a mark on their right hands or on their foreheads,
References for Revelation 13:16
17 so that they could not buy or sell unless they had the mark, which is the name of the beast or the number of its name.
References for Revelation 13:17
18 This calls for wisdom. Let the person who has insight calculate the number of the beast, for it is the number of a man.a That number is 666.
References for Revelation 13:18