"In the wheel of nature (And the tongue is a fire, a world of iniquity: so is the tongue among our members, that it defileth the whole body, and setteth on fire the course of nature; James 3:6)
sometimes one spoke is uppermost and by and by the contrary; 
there is a
constant ebbing and flowing, waxing and waning; from one extreme to the
other does the fashion of this world change, ever did, and ever will. ...To-morrow shall be as this day (the lowest valleys join to the highest mountains).
Solomon having shown the vanity of studies, pleasures, and business,
and made it to appear that happiness is not to be found in the schools
of the learned....he proceeds, in this chapter, further to prove his doctrine, and the
inference he had drawn from it, That therefore we should cheerfully
content ourselves with, and make use of, what God has given us, by
showing,
- I. The mutability of all human affairs (v. 1-10).
- II. The immutability of the divine counsels concerning them and the unsearchableness of those counsels (v. 11-15).
-
III. The vanity of worldly honor and power, which are abused
for the support of oppression and persecution if men be not governed by
the fear of God in the use of them (v. 16). For a check to proud oppressors, and to show them their vanity, he reminds them,
- 1. That they will be called to account for it in the other world (v. 17).
- 2. That their condition, in reference to this world (for of that he speaks), is no better than that of the beasts (v. 18-21). And therefore he concludes that it is our wisdom to make use of what power we have for our own comfort, and not to oppress others with it." MatthewHenry