Isso é abordado no livro A História Secreta de Star Wars , em uma análise da evolução dos vários rascunhos que levam à versão final que todos conhecemos hoje.
A seção relevante no capítulo 2, "The Star Wars" é intitulada "A Força dos Outros" e continua:
It is interesting to note that the Force is not existent in this draft—the phrase “may the force of others be with you” is used, but it is merely a generic “good luck” phrase, and is used casually by various people in the script, as are expressions such as “thank god.” Most agree that it is a playoff of the Christian phrase “May God be with you,” intended as a sort of ambiguous science fiction version of a theistic colloquialism. When Lucas began writing the second draft he would transform the samurai-inspired Jedi-Bendu of the rough draft into characters based on E.E. Smith's Lensmen, making them super-powered warriors. In determining the source of their power, Lucas took his “force of others” reference and turned it into a supernatural power, coupled with a crystal called the Kiber crystal which acts in a similar manner to the Lensmen’s lenses, increasing one’s natural abilities.
Uma amostra grátis do livro está disponível no link e a passagem citada começa na página 75.