Kisshu fushin actual meaning

Question

Okay,first off:I am not really someone who studies japanese or is a native speaker but I am doing karate¹ for some years and I hear some words or phrases here and there.There is one common saying from Shoshin Nagamine:

Once when asked for a brief definition of a good Karate person, Osensei Shoshin Nagamine replied: Kisshu fushin, Oni te hotoke kokoro. A demon's hand, a saint's heart.

This is mostly abbreviated with Kisshu fushin.As per online tools,there are no translations available that would explain this. As far as I can see, "Oni te hotoke kokoro" would pretty much mean "Demon with the spirit of a saint"(as I know that Onis are some sort of japanese demons and the rest of it got translated to somewhat related things).But what does Kisshu fushin stand for?

Plus:explaining the whole sentence would be very nice ;)

^{1) I hope that you are not tired of explaining language to some ordinary karateguy :D}

Answer 1

"Kishu busshin" and "Oni te hotoke kokoro" mean the same thing. The first uses Sino-Japanese pronunciations which might be hard to understand if you're hearing the word for the first time. The second uses native Japanese pronunciations, which would be easier to understand for a Japanese speaker. It would be like saying some complicated word formed from Latin roots and then explaining its etymology in everyday English.