Proverbs 30:32 Shut My Mouth

If you play the fool and exalt yourself,
    or if you plan evil,
    clap your hand over your mouth!

"Well, shut my mouth!"

Whew, how many times do I wish I had? How many negative consequences could I have avoided? And are you anything like me here?
Agur must have read all of the admonitions from Solomon to "watch your tongue" but he felt compelled here to tell us again . . . maybe because we need so often to be reminded? (Grin)

Exalting oneself is definitely playing the fool -- the opposite of that is humility. Humility is something that we gain and practice as we grow in wisdom and grace. I found a quote from Easton's 1897 Bible Dictionary that helps:

"a prominent Christian grace. It is a state of mind well pleasing to God; it preserves the soul in tranquility and makes us patient under trials."

David told us:

He guides the humble in what is right
    and teaches them his way. Ps 25:9

And Peter, too:

Clothe yourselves, all of you, with humility toward one another, for “God opposes the proud but gives grace to the humble.” I Peter 5:5b

Now, as for the second half of the verse,  perhaps we don't often "plan" evil, but are there times when we say something that isn't very nice? About someone else? You know, when we are out in public, at church, amongst Christian friends, we may do a good job of being careful. We may think before we speak in those times. But when we are at home, do we "let our hair down"? Do we whine, complain, yell, or worse, and after all, they're family so they have to put up with us? Ouch.
This is a very old concept, but let's try to remember this acrostic:
                                    T -- Is it true?  
                                    H -- Is it helpful?  
                                     I -- Is it inspiring?
                                    N -- Is it necessary? (That one gets me a lot.)
                                    K -- Is it kind?
I think I shall post some of these verses around where I can see them. Often. Very often.

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. Eph. 4:29

Let your conversation be always full of grace, seasoned with salt, so that you may know how to answer everyone. Col. 4:6

Do not be quick with your mouth,
do not be hasty in your heart 
to utter anything before God.
God is in heaven,
and you are on earth,
so let your words be few. Eccl. 5:2

Maybe then I won't have to say, "Well, shut my mouth!"