yán yǒu wù, xíng yǒu héng 言有物，行有恒
Talk Substance; Act with Perseverance
What one talks or writes about should have a sound basis and substance; the language and words he uses should fit the actual context. Hyperbole, exaggeration or falsehood should be opposed. In doing anything, one must have perseverance and focus, stick to principle and honor his words. One should preserve until the goal is met and must never give up halfway. This term also means that one should take a realist approach, seek truth and act in good faith.
A man of virtue should talk substance and act with perseverance. (The Book of Changes)