Hisgalus 13:17-18

Orthodox Jewish Bible

¹⁷ And that no one should be able to buy or to sell except the one having the tav [mark], the name of the Chayyah (Beast, Anti-Moshiach) or the number of its name.

¹⁸ Here is chochmah: the one having binah, let him do the gematria and get the mispar (number) of the Chayyah (Anti-Moshiach), for it is the mispar (number) of a man, and the mispar of it is SHESH ME’OT V’SHISHIM VASHESH (666).