This seems like such a simple concept to understand, and yet a difficult skill to master:  taming our tongues.
Let’s explore this a bit…

Ephesians 4:29-32
Let no harmful word come out of your mouth, but only what is beneficial for building others up according to the need, so that it gives grace to those who hear it. ³⁰ Do not grieve the Ruach ha-Kodesh of God, by whom you were sealed for the day of redemption. ³¹ Get rid of all bitterness and rage and anger and quarreling and slander, along with all malice. ³² Instead, be kind to one another, compassionate, forgiving each other just as God in Messiah also forgave you.

1Peter 3:8-10 [Quoting Psalm 34]
⁸ Finally, all of you be harmonious, sympathetic, brotherly, tenderhearted, humble-minded. ⁹ Do not repay evil for evil or insult for insult, but give a blessing instead—it is for this reason you were called, so that you might inherit a blessing.
¹⁰ For, “The one who loves life,
     wanting to see good days,
     must keep his tongue from evil
     and his lips from speaking deceit.

Proverbs 15:4
A healing tongue is a tree of life,
but a deceitful one crushes the spirit.

Proverbs 21:23
Whoever guards his mouth and tongue
keeps his soul out of troubles.

Psalm 141:3
Set a guard, Elohim, over my mouth.
Keep watch over the door of my lips.

James 1:19-20
¹⁹ Know this, my dear brothers and sisters: let every person be quick to listen, slow to speak, and slow to anger— ²⁰ for human anger doesn’t produce the righteousness of God.

This is just a small sampling of scripture pertaining to our words.
There are many more if you’d like to go find them.
If I were to boil this idea into just a few bullet points, I’d do this:
1.  Do not lie
2.  Do not gossip
3.  Do not use profanity
4.  Do not say things to be hurtful, even if they are true

Let’s use our words to build one another up.
Tell the truth in love.
Do not argue with one another.

Let’s take a quick look at the unintended consequences of spoken words in scripture.
Genesis 31—
³⁰ So now, when you up and left because you really missed your father’s house, why did you steal my gods?”
³¹ In response, Jacob said to Laban, “Because I was afraid, for I thought, ‘Suppose you snatch your daughters away from me.’ ³² Anyone with whom you find your gods shall not live. In front of our relatives, identify whatever is yours that is with me, and take it back.” (But Jacob did not know that Rachel had stolen them.)
³³ So Laban went into Jacob’s tent, and Leah’s tent and into the tent of the two maids, but he found nothing. Then he went out of Leah’s tent and entered Rachel’s tent. ³⁴ (Now Rachel had taken the idols, put them in the camel’s saddlebag and sat on them.) So Laban felt around the entire tent but did not find them. ³⁵ She said to her father, “Let not my lord be angry that I cannot rise before you, for I am having the way of women.” So he searched but did not find the idols.

When Jacob leaves the household of Laban, with Leah and Rachel, and all of his belongings, he does so without telling Laban of his departure.
Laban “hotly pursues” them, and seems to be angry with Jacob for several reasons.
1.  He left in secrecy.
2.  He took his wives, Laban’s daughters, without giving him a chance to say goodbye.
3.  Someone had stolen his false gods, his idols.

When we see what actions play out, a search for the false gods takes precedent over all of the issues.  This seems to indicate what was of most importance to Laban.
We see in the story that it was Rachel, Jacob’s favorite wife whom he loved most, that had taken the idols.
Without realizing he was cursing his beloved, Jacob says the following in verse 32
“Anyone with whom you find your gods shall not live.”

While Jacob may have been trying to do the honorable thing with regards to this theft, words have consequences.

We see this just a short time later:
Genesis 35:16-20

Rachel’s Death in Childbirth

¹⁶ Then they traveled from Beth-El, and while they were still a distance from entering Ephrath, Rachel began to give birth, but her labor was difficult. ¹⁷ While she was struggling to give birth, the midwife said to her, “Don’t be afraid, for this is also a son for you.” ¹⁸ Now as her soul was departing (for she died), she named him Ben-Oni, but his father named him Benjamin. ¹⁹ Then Rachel died and was buried on the way to Ephrath (that is, Bethlehem). ²⁰ Jacob set up a memorial stone over her grave. (It is the memorial stone over Rachel’s grave to this day.)

I’m guessing that Jacob had meant that if they found the idols, the thief would have been put to death, in order to maintain his integrity with Laban.  He had no idea that his favorite wife had taken the idols, and speaking this curse on her, unknowingly, set events in motion, causing great grief for Jacob.

Think on these things.
Set a goal to monitor your words. 
Let only good and productive things escape your lips.

2Corinthian 10:5
We are taking every thought captive to the obedience of Messiah…