The Teacher seems to have known many fools and many unjust and irresponsible rulers! At least, these are the topics he continues to develop in today's passage.

Ecclesiastes 10:12-15 contrasts the words of wise and foolish people: a wise person's words are ″gracious″ and bring them favour, but a fool's words bring them harm (see also Proverbs 14:3). The Teacher's point here relates to life's uncertainty (Ecclesiastes 10:14): ″No one knows what is coming″. Wise people accept this; fools prefer to bluster, multiplying words to convince themselves that all will be well. As a result their work brings them weariness (v. 15): the weariness and frustration of unproductive toil as their over-optimistic plans are derailed by events for which they did not make allowance.

The Teacher again takes up the theme of human limitations (see 1:3-11), particularly our limited knowledge (see 3:9-11). The sensible response to an uncertain world is to be modest and cautious in one's plans. Much human effort is unfruitful because it is misconceived.

(NB: ″wise″ and ″foolish″ are not synonyms for ″intelligent″ and ″stupid″. Intelligent people can persuade themselves to follow unwise plans: in fact, they can sometimes produce particularly clever arguments in favour of such plans.)

The Teacher now considers a particular category of thoughtless fools: lazy and irresponsible rulers (10:16-20); rulers who enjoy the perks of the job (royal robes, great wealth, lavish meals) without doing the job itself; rulers who let the roof leak (v. 18) while spending money on fine dining and revelry. This is the root of corruption: rulers and officials who care more about advancing their own prospects and lining their pockets than serving their people. Such people are a disgrace; they deprive citizens of what is rightfully theirs.

But they have ears (v. 20)! They are able to punish dissenters! So don't give in to the desire to criticise them. Such a desire may be understandable, but it is not wise. In a corrupt regime, informers are never lacking. There are people who advance their cause by reporting others as traitors. You cannot charm a snake by slapping it, so don't bad-mouth the king. Don't even think of it!

Again the Teacher underscores his favourite point: recognise your limits; work out what you can realistically hope to achieve and stick to that. This is the course of wisdom. Giving way to frustration (in this case, voicing criticisms of the king) may undermine all you have worked for. Saying what you really think may be satisfying at the time, but later it will hurt you and perhaps others as well. Foolish words are never a good idea (v. 12).