When I read the story, I found "なかれ"this word occurred several times.
「若い衆、知らない人を信用するでなかれ。」
「お前の持っていたお守りのおかげで命拾いしたのじゃ。望みすぎるなかれ。ここに幸なかれ。」
I looked it up and the sentences my dictionary provide are either Verb+なかれ or Noun+なかれ. But the first sentence above has "で" with it. Is it grammatically correct?
「信用{しんよう}するでなかれ」
is not "grammatical". No question about it.
However, 「なかれ」 in this context is only used as role language for an old male speaker in a children's story. A grammatical assessment of role language, to me, is sort of like barking up the wrong tree when it is imperative that the character must sound like an old man in a speech style that is still understandable to children from all parts of the country.
Questionable grammar is expected of in the genre. It is just how Japanese children's stories have developed.
If you found the phrase 「信用するでなかれ」 said by an adult in a writing aimed for other adults, then a discussion on the topic would certainly be productive and meaningful.
This time, however, it is just role language overriding fine grammar.
I believe the followings are okay:
- 信用するでない。 (explained here, somewhat colloquial)
- 信用するなかれ。 (orthodox classical grammar, sounds highly archaic)
- 信用することなかれ。 (orthodox classical grammar)
信用するでなかれ sounds a little odd at least to me, but my knowledge about classical Japanese is limited, and I cannot say it's incorrect with confidence.
EDIT: Of course I'm aware that this 昔話 is not a real archaic document, and the phrase 信用するでなかれ is produced by someone living in the modern era. Unsurprisingly, modern Japanese people (including myself) are not very good at the rules of archaic Japanese, and they sometimes come up with strange expressions.
At any rate, 信用するでなかれ sounds a little weird even as a modern role word, to the ears of a modern Japanese speaker like me. BCCWJ has literally zero example of such verb + でなかれ, whereas you can easily find lots of verb + (こと +) なかれ examples such as 言うなかれ, 侮るなかれ, 思い惑うことなかれ, 礼を乱すことなかれ, etc. So it can be safely said that verb + でなかれ is at least rare even as role language of wise old men, whether or not it's grammatically correct.
It is an archaic form of saying one must not or should not. It comes from 無かる, which means to not be or to be absent.
