In my NKJV, 10 of the 33 verses in Proverbs 15 are about the tongue/words of our mouth.
These verses remind me that James 3:6 says, “The tongue is a fire, a world of iniquity. The tongue is so set among our members that it defiles the whole body, and sets on fire the course of nature; and it is set on fire by hell.”
Jesus also said, “Out of the abundance of the heart the mouth speaks.” (Luke 6:45) In Mt. 15:18, He said, “Those things which proceed out of the mouth come from the heart, and they defile a man.”
If we have truly invited The Lord into our hearts, the abundance of our hearts will be good, pure things of love, full of wisdom and understanding. Therefore the words we speak, as a true heir of God, will build up others around us and will be a delight to The Lord.
If the words of our mouth are tearing others down, breaking the spirits of those around us, or stirring up anger then we need to examine our hearts, quite literally, and invite The Lord to be Lord of it all.
May the words of my mouth and the meditations of my heart be acceptable in Your sight, O Lord, my Strength and my Redeemer.