Exchanging letters and building worlds.
And ye shall not profane My holy name; but I will be hallowed among the children of Israel: I am HaShem who hallow you (Lev. 22, 32)
… it is written Do not profane (t'chal'lu) My holy Name (Lev. 22). If you make CHES into HEI, you have destroyed the world (it now says "do not praise My Name"). Every soul, praise Hashem (Psalms 102). If you make HEI into CHES ( it now reads "every soul profane G-d"), you destroy the world. Similarly, Hear Israel… Hashem is One (echad) (Deut. 7). If you make DALET into REISH, you destroy the world (it now says, " G-d is another"), as it says, Do not bow down to another G-d (Ex. 34).
They denied G-d (Yirmiah 5), if you make BEIT into KAF (it now reads "they denied like G-d"), you destroy the world.
There is no one holy like Hashem (Samuel I, 2). If you make KAF into BEIT (it now reads, "there is nothing holy in G-d"), you destroy the world… (Tanchuma 1) [ 1]
A few lines later, Tanchuma uses the technique of Al Tikrei. As we have previously discussed, it involves reading a word as if substituting one letter for another. It interprets the word AMUN as if written OMEN, changing the meaning from I (Wisdom) was by Him true (Proverbs 8) to I was by him a parent , which it interpreted as saying that the world was created through Wisdom. Isn't it curious that right after pointing out how substituting one letter for another destroys the world, the Midrash goes on to use precisely the method of substituting one letter for another ? While the warning against exchanging letters clearly relates only to ones that are similar in shape, this exegetic substitution is in pronunciation and not in spelling. Nevertheless, there are many substitutions of letters that appear to actually change the spelling as well.
The method of substituting letters goes beyond Al Tikrei. R. Menachem Kasher in notes to Tazria, Ch. 14, classifies letter substitutions into these basic groups.
1-4: ATBASH, ATBACH, ALBM, ACHS BTE
These methods known from gematria consist of separating alphabet into groups of letters and then exchanging the letters in corresponding position within the alphabet. For example, one can divide the Alef Beis into two groups - Aleph to Kaf, and Lamed to Tof. Since Tes and Reish, Beit and Mem, Aleph and Lamed are in corresponding position of each group, they can be exchanged, yielding a drash. This is how in Isaiah 7,1 the identity of the no-good king TovAl becomes Ramla, otherwise known as Pekach ben Ramalyahu (Numbers Rabbah 18).
5. Letters that have similar shape, such as Ches and Hei.
And you name shall not be called anymore Avram but Avraham shall your name be, for I had placed you to be father of nations (av hamon goyim) (Bar. 17,5)
R. Yochanan said: Where is the source for reading abbreviations as a method of the Torah? It states: Av Ra Ha M = Av Hamon Goyim…
H(ei) - ch aviv (precious) I have placed you for nations I have placed you for nations
6. Substituting letters AHOY (Aleph, Hei, Vav, Yud).
This kind of substitution is the most straightforward as it is found in Tanach, in that these letters are sometimes substituted one for another in the same word in different verses, see Ibn Ezra Genesis 8, 2.
7-8. Letters that are pronounced in the same general area in the throat or mouth .
An example is substituting Gimmel and Kaf, such as Ragil and Rachil, see Rashi Vayikra 19, 16.
9. Letters that are adjacent in the Alef Beis,
for example Aleph and Beis (Karav for Kara, brought by some commentators from Pirke D'Rabbi Eliezer 42 (but not found in our versions).
10. Miscellaneous substitutions,
i.e., reading kochav as kozav in reference to Bar Kochba (Lamentations Rabba 2,5).
R. Kasher himself offers a bold suggestion that some of these substitutions are based on Ancient Hebrew script and the similarity of certain letters' shape in that alphabet. While interesting for its scope and courage, this proposal does not appear fully satisfactory in resolving the mystery of letter substitution as method of derash. The fact that substitutions are not arbitrary but fall into these 10 groups, suggests that they are not simply a mnemonic device but rather a bon-fide interpretetative technique. We must continue to attempt to find a satisfying explanation for this method of interpretation; May Hashem enlighten us and open our eyes in his Torah.
1 Eitz Yosef points out that this passage seems to have been truncated, as it seems nothing to do with the rest of the paragraph. The version in midrash Chazis, introduces it with a sentence that proposes that even things which appear unimportant in the Torah, i.e. matters of spelling, can, if miscopied, destroy the world.
2 Although in this case, only the pronunciation is changed, Al Tikrei quite often involves letter substitution. See, for example, see here.