This one is dedicated to all those who just had to push the big red button. Incidentally, it’s somewhat antonymical to last week’s kotowaza.

触らぬ神に祟り無し
(Sawaranu kami ni tatari nashi; “Untouched gods won’t curse you.”)

Definition:

If it ain’t broke, don’t fix it. It’s best not to get involved. Let sleeping dogs lie. If you simply leave well enough alone, you’ll be able to avoid a lot of trouble.

Breakdown:

First we find the verb 触る (sawaru), “to touch.” Here it’s in the imperfective form to take the negative auxiliary verb ず (zu), itself in prenominal form. To be honest, I was confused about this for a while – I was expecting a conditional, and was ready to translate the expression as “If you don’t touch [it], the gods won’t curse you.” But that would have been wrong: the prenominal indicates that the negated verb modifies the following noun, giving us “untouched gods”! Thank goodness for grammar, eh?

Next we have 神 (kami), “spirit” or “god.” The particle に (ni) marks it, in this case with its directional function to indicate “from.” This is followed by another noun, 祟り (tatari), from the verb 祟る (tataru), “to curse,” “to haunt,” “to cause a bad outcome.” And finally we get the adjective of negation 無し (nashi) in sentence-final form.

Notes:

This is the sa entry of the Osaka Iroha karuta set.

Example sentence:

「死にたいのかよ？触らぬ神に祟り無しって言うだろう？」　「どの道もう触ったし、もう仕方ないから、手伝ってください！」

(“Shinitai no ka yo? Sawaranu kami ni tatari nashi tte iu darou?” “Dono michi mou sawatta shi, mou shikata nai kara, tetsudatte kudasai!”)

[“Do you want to get yourself killed? Don’t they say to let sleeping dogs lie?” “In any case they’re awake now. There’s no helping it. So won’t you please help?”]

Come on, Ashitaka, what was I JUST talking about? [Source]