Lamed Vavniks: The thirty-six righteous who sustain the world
In the earliest version of this idea in rabbinic literature, found in Gen. R. 49:3, there are forty-five, “fifteen in Babylon, thirty in the land of Israel.” There is no firm explanation for how the tradition settles upon the number thirty-six (Sanh. 97b). Perhaps it is symbolic of "abundant life": double the number eighteen, the number value of the word chai / "life." According to the “thirty-six” legend, most of the thirty-six are nisterim, unknown, anonymously doing their good work unnoticed by the world. A esoteric prooftext for the number is found in Isaiah 30:18 - "For the Eternal is a God of justice; fortunate are those who wait for Him." In Hebrew, the pronoun "for Him" has the numeric value of 36. Thus the verse is read as "...fortunate are those who wait - [the] 36"
(Thanks to the anonymous reader who called my attention to this Isa. verse)
The reward for their anonymous labors is that they are privileged to directly experience the Shekhinah. One of them in each generation is suitable to be the Messiah (Sanh. 97b; Chul. 45a; Gen. R. 35:2; Mid. Teh. 5:5; Zohar 2:151a).
The fine Holocaust novel by Andre Bart-Schwarz, The Last of the Just, employs this legend, but "christianizes" this Jewish tradition in that the book claims that the 36 are destined to suffer for the sake of sustaining the world. Suffering and myrtrdom is not a big element of the lamed-vavnik tradition