Whoever loves a pure heart and gracious speech will have the king as a friend. Proverbs 22v11 (NLT)
Loving a pure heart is about a sincere desire to do what is right. It is not about always being right. The same applies to gracious speech. Our sentences should be filled more with words that win others over not cause them to wince.
The tongue is the most accessible weapon on the planet and perhaps has done the most harm. The sheer power of the word to build up or destroy is frightening.
This small nugget of wisdom says that if kind, generous words gain us access, acceptance and a hearing with the most powerful of people, it will surely do the same or more for our peers etc.
He who loves purity of heart, and whose speech is gracious, will have the king as his friend. Proverbs 22v11 (ESV)