To every thing there is a {a} season, and a time to every purpose under the heaven:

(a) He speaks of this diversity of time for two causes first to declare that there is nothing in this world perpetual: next to teach us not to be grieved, if we have not all things at once according to our desires, neither enjoy them so long as we would wish.

Wesley's Notes

3:1 A season - A certain time appointed by God for its being and continuance, which no human wit or providence can alter. And by virtue of this appointment of God, all vicissitudes which happen in the world, whether comforts or calamities, come to pass. Which is here added to prove the principal proposition, That all things below are vain, and happiness is not to be found in them, because of their great uncertainty, and mutability, and transitoriness, and because they are so much out of the reach and power of men, and wholly in the disposal of God. Purpose - Not only natural, but even the voluntary actions of men, are ordered and disposed by God. But it must be considered, that he does not here speak of a time allowed by God, wherein all the following things may lawfully be done, but only of a time fixed by God, in which they are actually done.

Jamieson-Fausset-Brown Bible Commentary

CHAPTER 3

Ec 3:1-22.

Earthly pursuits are no doubt lawful in their proper time and order (Ec 3:1-8), but unprofitable when out of time and place; as for instance, when pursued as the solid and chief good (Ec 3:9, 10); whereas God makes everything beautiful in its season, which man obscurely comprehends (Ec 3:11). God allows man to enjoy moderately and virtuously His earthly gifts (Ec 3:12, 13). What consoles us amidst the instability of earthly blessings is, God's counsels are immutable (Ec 3:14).

1. Man has his appointed cycle of seasons and vicissitudes, as the sun, wind, and water (Ec 1:5-7).

purpose-as there is a fixed "season" in God's "purposes" (for example, He has fixed the "time" when man is "to be born," and "to die," Ec 3:2), so there is a lawful "time" for man to carry out his "purposes" and inclinations. God does not condemn, but approves of, the use of earthly blessings (Ec 3:12); it is the abuse that He condemns, the making them the chief end (1Co 7:31). The earth, without human desires, love, taste, joy, sorrow, would be a dreary waste, without water; but, on the other hand, the misplacing and excess of them, as of a flood, need control. Reason and revelation are given to control them.

Matthew Henry's Concise Commentary

3:1-10 To expect unchanging happiness in a changing world, must end in disappointment. To bring ourselves to our state in life, is our duty and wisdom in this world. God's whole plan for the government of the world will be found altogether wise, just, and good. Then let us seize the favourable opportunity for every good purpose and work. The time to die is fast approaching. Thus labour and sorrow fill the world. This is given us, that we may always have something to do; none were sent into the world to be idle.