Have you ever used a mortar and pestle? The purpose of the apparatus is to crush, grind, or mix whatever is in the bowl (mortar). Something is placed within the mortar, then through the action of the repeated blows and grinding of the pestle, the object in the mortar begins to change its form. If it is corn, eventually the hardened pellet of corn will become like fine flour. When leaves are put in the mortar, the pounding begins to release the oils contained in the leaves, allowing a fragrance to be released. The bowl portion of the device is nothing without the "tool of action" (the pestle). It is the pestle which accomplishes the "transition" of substance from one form to another.
Pound on a fool all you like—you can't pound out foolishness. (Proverbs 27:22 The Message)
You cannot separate fools from their foolishness, even though you grind them like grain with mortar and pestle. (Proverbs 27:22 NLT)
So, our passage tells us something very interesting - fools are not easily "changed" in their "form"! Even in the "mortar and pestle" of life - no amount of "pounding, crushing, or grinding" is going to change their folly! If you have ever tried to change the foolishness of another person's ways, you might just realize this fact!
If you have ever asked God to deal with the foolishness of your own heart, you have probably come up-close-and-personal with the struggle to resist his "pestle"! Yet, as he brings down the "pestle", it is with grace - he is never crushing us to hurt us, but to make us into something which no longer resembles the original form of what we were.
The most common symbol of a pharmacy is the mortar and pestle. It came to be known as the method of "compounding" substances we use in medicines today. Yet, as you may well imagine, if the mortar is not cleaned well between uses, what goes into the mortar to be "mixed" the next time will be contaminated by the stuff which remains from the last time it was used. God takes great care to never allow the impurities of our lives to "contaminate" the final product he is after in his "mixing" process. To our talents, he adds his grace - refining them through the actions of the pestle against the mortar until they become one.
In some cultures, a large device is used, made of a hollowed log and a large piece of wood which has been formed into a pestle. The purpose of the device is to remove the husk of the grain. It is not so much to grind it into fine flour, but to get it to the point of being "penetrable" by the de-husking process. Sometimes, God needs to do some "husk removing" in our lives before we are ready to be "penetrated" with his grace.
In getting back to our passage, it is quite good advice which Solomon gives us. Try as "we" might, we cannot separate a fool from his folly. Try as "we" might, we cannot separate ourselves from our own foolishness. Then why do we get so "down" on ourselves when we "try to live right" and find ourselves failing? God has designed us to be "separated" from our foolishness (de-husked) through the actions of his repeated "blows" of grace in our lives. Think of it this way:
His mortar is the present trial. His pestle bring the repeated "blows" which will "crush out" our resistance to change. In the end - the substance which is produced has greater value - and a more pleasant "aroma"!
If we really want to be separated from our folly, then we need to embrace the grace which is present in the trial. The trial is a separating process - making us "penetrable" to God's touch. The process is difficult, but the end result is awesome.