The Rule of Three has its possible prototype in a piece of Wiccan liturgy which first appeared in print in Gerald Gardner's 1949 novel High Magic's Aid:
'Thou hast obeyed the Law. But mark well, when thou receivest good, so equally art bound to return good threefold.' (For this is the joke in witchcraft, the witch knows, though the initiate does not, that she will get three times what she gave, so she does not strike hard.)
