Proverbs 4:23-24

Watch over you heart with all diligence, for from it flow the springs of life. Put away from you a deceitful (lying, misleading) mouth and put devious lips far from you.

Our heart believes what we say! If your word isn’t spoken with integrity than your heart will not trust you. Our authority and speaking the word depends on us having integrity. What we speak matters! Which is why we are to watch over our hearts and keep only living water flowing out of our mouths.