If any man offend not in word, the same is a perfect man, and able also to bridle the whole body.  James 3:2

For he that will love life, and see good days, let him refrain his tongue from evil, and his lips that they speak no guile  I Peter 3:10

He who has become aware of his sins has controlled his tongue, but a talkative person has not yet come to know himself as he should. St. John Climacus

If Moses, who was a god to Pharoah, was shut out from the Land of Promise because of one word, how much more will not the evil speech of our tongue, by which we offend and hurt both God and man, shut us out from heaven? St. Ephairm the Syrian

Many abstain from meat, milk and other food which God has not forbidden and which was even given as a blessing of people who have learned the truth and know how to partake of these things with thanksgiving (I Tim. 4:34). But the same abstemious, devout-living people, give scandal by their action, and spread scandal with their tongue like an incendiary fire. St. Tikhon of Zadonsk

In general, loquacity opens the doors of the soul, and the devout warmth of the heart at once escapes. Empty talk does the same, but even more so…Empty talk is the door to criticism and slander, the spreader of false rumors and opinions, the sower of discord and strife. It stifles the taste for mental work and almost always serves as a cover for the absence of sound knowledge… Bishop Theophan the Recluse