The main issue of his counsel is not the number of words we say, though we are cautioned to be neither rash nor hasty, so our words should be few. Rather, the main thrust of his counsel lies in verses 4-7. His concern is whether we thoughtfully follow through and keep our promises regardless of when, where, or to whom they are made, that is, unless following through would cause us to sin. The major sin that he is concerned about, despite not being directly stated, is ultimately the matter of hypocrisy.
Hypocrisy is misrepresenting who and what we really are. Solomon's concern is probably not deliberate hypocrisy but forgetfulness and carelessness in our witness. In other words, we cannot allow ourselves to let slip from our minds who we are and whom we represent. It is a matter of not being as disciplined and focused as we need to be. Focus is that important to the proper use of faith. Do we ever “let our hair down”? Is it possible that we display hypocrisy because we are not as zealous as we need to be?
Notice the string of clues in the terms he uses to reveal that undisciplined carelessness is the root of the problem, which triggers hypocrisy, a sin that a person can fall into without effort. He uses “fools” (three times), “rash,” “hastily,” “do not let,” “do not delay,” “error,” “excuse,” and “words be few.” Overall, he paints a picture of a person of undisciplined mind who prattles about whatever amuses him at the time without considering the effects of what he is saying. He is later caught and exposed by, as Solomon says, the messenger of God.
I Peter 1:13 and James 1:22 provide sound counsel about what must be done to eliminate the accusations of a loose tongue. I Peter 1:13 charges us to, “Gird up the loins of your mind,” and James 1:22 adds, “But be doers of the word, and not hearers only, deceiving yourselves.” Remaining focused on achieving the goal set before us to follow through in obedience to God will meet the responsibility of paying all our vows to God.
Sometimes, it slips our minds that we made a covenant with God, and in return for our pledge, gave Him our lives as living sacrifices. That covenant seals our holy promise to Him that, if He will forgive our sins based on our repentance and faith in Christ's sacrifice, we in turn will devote our lives in service to Him. Thus, we must keep our wits about us because, though God is merciful, everything should matter to us.
The “messenger of God” Solomon mentions is anybody or any circumstance that triggers the revelation in our minds that we have sinned or are continuing in a sin. Solomon is showing that God is faithful to bring the knowledge of our sins to mind so that we might repent, and that, of course, causes us a measure of disappointment that we have once again fallen short and failed to honor and glorify God.