The Geneva Bible Translation Notes, [1599], at sacred-texts.com
(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.
I have seen the labour, which God hath given to the sons of men (b) to be exercised in it.
(b) Read (Ecc 1:13).
He hath made every [thing] beautiful in its time: also he hath set the (c) world in their heart, so that no man can find out the work that God maketh from the beginning to the end.
(c) God has given man a desire and affection to seek out the things of this world, and to labour in it.
And also that every man should eat and drink, and enjoy the good of all his labour, it [is] the (d) gift of God.
(d) Read (Ecc 2:24) and these places declare that we should do all things with sobriety and in the fear of God, as he gives not his gifts to the intent that they should be abused.
I know that, whatever God doeth, it shall be for (e) ever: nothing can be added to it, nor any thing taken from it: and God doeth [it], that [men] should fear before him.
(e) That is, man will never be able to prevent God's work, but as he has determined so it will come to pass.
That which hath been is now; and that which is to be hath already been; and God (f) requireth that which is past.
(f) God only causes what which is past, to return.
I said in my heart, God shall judge the righteous and the wicked: for [there is] a time (g) there for every purpose and for every work.
(g) Meaning, with God, however man neglects his duty.
I said in my heart concerning the state of the sons of men, that God might (h) tempt them, and that they might see that they themselves are beasts.
(h) And made them pure in their first creation.
For that which befalleth the sons of men befalleth beasts; even one thing (i) befalleth them: as the one dieth, so dieth the other; yea, they have all one breath; so that a man hath no preeminence above a beast: for all [is] vanity.
(i) Man is not able by his reason and judgment to put differences between man and beast, as concerning those things to which both are subject: for the eye cannot judge any otherwise of a man being dead than of a beast, which is dead: yet by the word of God and faith we easily know the diversity as in (Ecc 3:21).
Who (k) knoweth the spirit of man that goeth upward, and the spirit of the beast that goeth downward to the earth?
(k) Meaning, that reason cannot comprehend that which faith believes in.
Wherefore I perceive that [there is] nothing better, than that a man should (l) rejoice in his own works; for that [is] his portion: for who shall bring him to see what shall be after him?
(l) By the often repetition of this sentence as in (Ecc 2:24, Ecc 3:12, Ecc 3:22, Ecc 5:17, Ecc 8:15) he declares that man by reason can comprehend nothing better in this life than to use the gifts of God soberly and comfortably: for to know further, is a special gift of God revealed by his Spirit.