Psalms 19:14 Let the words of my mouth, and the meditation of my heart, be acceptable in Thy sight, O Lord, my strength, and my redeemer.
Psalms 35:28 My tongue shall speak of Thy righteousness and of Thy praise all the day long.
Proverbs 16:24 Pleasant words are as an honeycomb, sweet to the soul, and health to the bones.
Proverbs 17:27 He that hath knowledge spareth his words: and a man of understanding is of an excellent spirit.
Proverbs 18:21a Death and life are in the power of the tongue.
Proverbs 29:11 A fool uttereth all his mind: but a wise man keepeth it in till afterwards.
Matthew 12:34b Out of the abundance of the heart the mouth speaketh.
Matthew 12:36,37 Every idle word that men shall speak, they shall give account thereof in the day of judgment. For by thy words thou shalt be justified, and by thy words thou shalt be condemned.
Ephesians 4:29 Let no corrupt communication proceed out of your mouth, but that which is good to the use of edifying, that it may minister grace unto the hearers.
2 Timothy 2:16 But shun profane and vain babblings: for they will increase unto more ungodliness.
2 Timothy 2:24 The servant of the Lord must not strive; but be gentle unto all men, apt to teach, patient.
James 1:19 Wherefore, my beloved brethren, let every man be swift to hear, slow to speak, slow to wrath.
James 1:26 If any man among you seem to be religious, and bridleth not his tongue, but deceiveth his own heart, this man’s religion is vain.
(See James 3-“The Tongue Chapter.”)