The above sentence has been attributed to O'Sensei and I'd like to use it as a motto for my dojo's website.

Problem: I can't find a reliable source about when/where he said this. Or a proper Japanese version of the original sentence, either.

I have tried to cobble together a Japanese version first, hoping to be able to google for it and see if I can get something from Japanese sites... no success so far.

Can someone please point me to a credible source, and possibly to the correct japanese quote used by Ueshiba?