In the video we showed at this meeting, Mindful Speech, Tara Brach suggests that if we had no other practice than bringing mindfulness into conversation, that it would transform our lives. It is extraordinarily difficult to remain mindful in conversation, especially if we aim to both speak truthfully and do it in a way that is not harmful or disrespectful. At the end of the video, Tara shares this quote from Martin Niemöller, a pastor who spoke out publicly against Hitler and as a result spent seven years in concentration camps:

First they came for the Socialists, and I did not speak out—
Because I was not a Socialist.

Then they came for the Trade Unionists, and I did not speak out— 
Because I was not a Trade Unionist.

Then they came for the Jews, and I did not speak out— 
Because I was not a Jew.

Then they came for me—and there was no one left to speak for me.

     I believe we are obliged to tell the truth. Telling the truth is a way we take care of people. The Buddha taught complete honesty, with the extra instruction that everything a person says should be truthful and helpful.
     When the Buddha taught Right Speech, he provided a guide for making corrections. Admonitions, he said, should be timely, truthful, gentle, kind, and helpful. When I tell people those criteria, they often exclaim, “But then no one could ever admonish anyone!” I think otherwise. I think with Right Speech people can make suggestions or observations in a way that the other person can hear and see them without feeling diminished.
           - from It's Easier Than You Think by Sylvia Boorstein

     Living with integrity means: Not settling for less than what you know you deserve in your relationships. Asking for what you want and need from others. Speaking your truth, even though it might create conflict or tension. Behaving in ways that are in harmony with your personal values. Making choices based on what you believe, and not what others believe.
           - Barbara deAngelis

     A traditional Zen teaching story begins with the account of elders in a rural Japanese village bringing a newborn infant to the mountaintop home of the local Zen priest, knocking at the gate, and saying, "The unmarried woman who is this child's mother says that you are the father. You need to take care of it." The priest says, "Is that so?" and accepts the baby. Three years later the elders return, saying, "The real father of the child has returned to the village, confessed, and agreed to marry the mother, and now you need to give the child back to us." The priest says, "Is that so?" and gives them the child.
           - from Pay Attention For Goodness' Sake by Sylvia Boorstein (for the rest of this excerpt, see Now and Zen)

     The Buddha singled out right speech as one aspect of the path to awakening, the Eightfold Path, and of the ten unwholesome actions, four involve speech. This should be a wake-up call, a bell of mindfulness ringing before we speak. But do we really make speech part of our spiritual path, or do we relegate it to some place of lesser importance in our lives? When we pay attention, we see how much our words affect our relationships with other people, condition our own minds, and lead to karmic consequences in the future. The care it takes to avoid harmful speech creates a vast playing field of mindfulness in our daily lives.
     Lying is the first in this group of unskillful verbal actions. There are many kinds of false speech, from slight exaggerations and humorous untruths, to falsehoods whose purpose is self-protection or protection of others, to deliberate lies told with malicious intent, causing divisiveness and harm.
           - from One Dharma by Joseph Goldstein

     My Zen teacher used to say, "Kind speech is not always kind." Generally, of course, a gentle word or compliment is most conducive to serenity, goodwill, and waking up. But, just as you would not refuse to vaccinate your child because the procedure is painful, once in a while there's that fleeting moment where the kindest thing you can do for another is to utter a severe word or sharp observation that may hurt momentarily. The child who's about to dash into a busy street may need to be told sharply to stop.
     Before you speak, you must examine your own mind and motive. If you're trying to put someone down, or if you're about to speak from malice or spite, then don't speak at all. But if in that moment you must tell someone, "I'm saddened by how you treated Jim this morning. I think you owe him an apology," then say it. Or perhaps for a friend's health, sanity and well-being, you need to say, "I think you've got a problem with alcohol. If you continue to drink as you do now, you will accomplish little else. And you will cause your family to suffer as well." It could hurt. It could appear very cutting at that moment, from the outside. But that doesn't necessarily mean it's not kind. It depends on your motive. Be sure to first observe your own mind. It's impossible to specify a proper response in advance. Every situation must be dealt with on a case-by-case basis.
     If you would awaken, the point is not so much to be concerned with the actual words you speak, or even their tone. Instead, be concerned with observing your own heart and mind. Then speak out of your awareness of what you observe - in your heart, mind, and situation. The words you select, and their tone, will follow appropriately. And you will be speaking and listening out of wisdom and compassion.
           - from Buddhism Plain and Simple by Steve Hagen

     Speak from the heart. Don’t talk bullshit. Say something real, not something impressive. When I speak from the heart, I allow myself to know what is important to me. When we are afraid to say something, it’s not so much other people we are afraid of, it’s that we’re afraid of what we ourselves might think.
     Listen with your whole body. Listening means doing less. When we’re not trying to influence the other person in any way, we are simply present. Then a vast peace appears. Gratitude, the moon, and the stars enter the room. Listening is a form of love. It’s a way to keep company with each other in the night
     When all the voices are in the room, it’s a good day. We invite people to speak who normally stay silent. People can trust their own moves and be interested in their own lives. If we want to wake up, we probably will.
          - from Enlightenment Is Something We Do Together by Jon Tarrant