as long as I have life within me,
the breath of God in my nostrils,
my lips will not speak wickedness,
and my tongue will utter no deceit.
Job 27:3, 4 NIV

My tongue will speak of your righteousness and of your praises all day long.
Psalms 35:28 NIV

He whose walk is blameless
and who does what is righteous,
who speaks the truth from his heart
and has no slander on his tongue,
who does his neighbor no wrong
and casts no slur on his fellowman…
He who does these things
will never be shaken.
Psalm 15:2, 3, 5 NIV

Listen, for I have worthy things to say; I open my lips to speak what is right.
Proverbs 8:6 NIV

He who walks righteously
and speaks what is right,
who rejects gain from extortion
and keeps his hand from accepting bribes,
who stops his ears against plots of murder
and shuts his eyes against contemplating evil-
this is the man who will dwell on the heights,
whose refuge will be the mountain fortress.
His bread will be supplied,
and water will not fail him.
Isaiah 33:15, 16 NIV

So the spies questioned him: “Teacher, we know that you speak and teach what is right, and that you do not show partiality but teach the way of God in accordance with the truth.
Luke 20:21 NIV

Do not let any unwholesome talk come out of your mouths, but only what is helpful for building others up according to their needs, that it may benefit those who listen.
Ephesians 4:29 NIV

Not many of you should presume to be teachers, my brothers, because you know that we who teach will be judged more strictly. 2We all stumble in many ways. If anyone is never at fault in what he says, he is a perfect man, able to keep his whole body in check.
When we put bits into the mouths of horses to make them obey us, we can turn the whole animal. Or take ships as an example. Although they are so large and are driven by strong winds, they are steered by a very small rudder wherever the pilot wants to go. Likewise the tongue is a small part of the body, but it makes great boasts. Consider what a great forest is set on fire by a small spark. The tongue also is a fire, a world of evil among the parts of the body. It corrupts the whole person, sets the whole course of his life on fire, and is itself set on fire by hell.
All kinds of animals, birds, reptiles and creatures of the sea are being tamed and have been tamed by man, 8but no man can tame the tongue. It is a restless evil, full of deadly poison.
With the tongue we praise our Lord and Father, and with it we curse men, who have been made in God’s likeness. Out of the same mouth come praise and cursing. My brothers, this should not be. Can both fresh water and salt water flow from the same spring? My brothers, can a fig tree bear olives, or a grapevine bear figs? Neither can a salt spring produce fresh water.
James 3:1-12 NIV

For, “Whoever would love life and see good days must keep his tongue from evil and his lips from deceitful speech.
1 Peter 3:10 NIV