Because, therefore - , Or, as in Ecclesiastes 8:7, "for."
The possibility of God's time and judgment being in opposition to a king's purpose or commandment Ecclesiastes 8:5, suggests the thought that such discord is a misery (evil, Ecclesiastes 6:1) common to man (or, mankind).

To every purpose there is time - חפץ chaphets, every volition, every thing that depends on the will of man. He has generally the opportunity to do whatever he purposes; and as his purposes are frequently evil, his acts are so too: and in consequence his misery is great.

Because to every purpose there is time and judgment, therefore the (f) misery of man [is] great upon him.
(f) Man by himself is miserable, and therefore should do nothing to increase the same, but to work all things by wisdom and counsel.

Because to every purpose there is time and judgment,.... There is a fit season, and a right and proper manner of doing everything that is to be done; see Ecclesiastes 3:1; which a wise man discerns; and which when a man hits upon, it prevents a great deal of mischief, which for want of it comes upon men, as the following clause shows; some refer this to the punishment of the wicked, and to a future judgment. So the Targum,
"to every business there is a time good and evil, and according to the judgment of truth the whole world is judged;''
and to the same purpose Jarchi,
"there is a time fixed for the visitation of the wicked, and there is judgment before the Lord; this is vengeance or punishment;''
therefore the misery of man is great upon him; he not observing the right time and manner of doing what he ought, brings much trouble upon himself; his days are few and full trouble, and every day has a sufficiency of evil in because of the evil of sin, the evil of misery presses upon him, and is a heavy burden on him Jarchi's note is,
"when the wickedness of a man is great, then cometh his visitation.''

God has, in wisdom, kept away from us the knowledge of future events, that we may be always ready for changes. We must all die, no flight or hiding-place can save us, nor are there any weapons of effectual resistance. Ninety thousand die every day, upwards of sixty every minute, and one every moment. How solemn the thought! Oh that men were wise, that they understood these things, that they would consider their latter end! The believer alone is prepared to meet the solemn summons. Wickedness, by which men often escape human justice, cannot secure from death.

therefore the misery, &c.--because the foolish sinner does not think of the right "times" and the "judgment."

"For there is a time and decision for everything, for the wickedness of man becomes too great." From Ecclesiastes 8:6 there follow four clauses with כּי; by such monotonous repetition of one and the same word, the author also elsewhere renders the exposition difficult, affording too free a space for understanding the כי as confirming, or as hypothetical, and for co-ordinating or subordinating to each other the clauses with כי. Presupposing the correctness of our exposition of Ecclesiastes 8:5, the clause Ecclesiastes 8:6 with כי may be rendered parenthetically, and that with כי in Ecclesiastes 8:6 hypothetically: "an end and decision the heart of the wise man will come to experience (because for everything there is an end and decision), supposing that the wickedness of man has become great upon him, i.e., his burden of guilt has reached its full measure." We suppose thereby (1) that בּה, which appears from the accent on the ult. to be an adj., can also be the 3rd pret., since before ע the tone has gone back to h (cf. Genesis 26:10; Isaiah 11:1), to protect it from being put aside; but generally the accenting of such forms of עע hovers between the penult. and the ult., e.g., Psalm 69:5; Psalm 55:22; Proverbs 14:19. Then (2) that עליו goes back to האדם without distinction of persons, which has a support in Ecclesiastes 6:1, and that thus a great רעה is meant lying upon man, which finally finds its punishment. But this view of the relation of the clauses fails, in that it affords no connection for Ecclesiastes 8:7. It appears to be best to co-ordinate all the four כי as members of one chain of proof, which reaches its point in Ecclesiastes 8:8, viz., in the following manner: the heart of a wise man will see the time and the judgment of the ruler, laying to his heart the temptation to rebellion; for (1) as the author has already said, Ecclesiastes 3:17 : "God will judge the righteous as well as the wicked, for there is with Him a time for every purpose and for every act;" (2) the wickedness of man (by which, as Ecclesiastes 3:9 shows, despots are aimed at) which he has committed, becomes great upon him, so that suddenly at once the judgment of God will break in upon him; (3) he knows not what will be done; (4) no one can tell him how (quomodo) it, the future, will be, so that he might in any way anticipate it - the judgment will overwhelm him unexpectedly and irretrievably: wickedness does not save its possessor.

Because - There is a fit way and season for the accomplishment of every business, which is known to God, but for the most part hidden from man. Therefore - Because there are few who have wisdom to discern this, most men expose themselves to manifold miseries.