Yp, the very first one... And that appears to be that, unless one counts the novels. Or opts to treat some of Kor's utterances as proverbs because, you know, anything a wise old man says must be zen. Especially if it includes a lot of belching.
Which is not really a Klingon proverb, but is from various Earth sources
Then again, so is everything else about Klingons. Or Star Trek in general. Hell, "Live long and prosper!" is an authentic Finnish greeting well preceding TOS... And no doubt an authentic greeting in about two thousand other human cultures past and present as well.