John Gill's Exposition of the Whole Bible
Ecclesiastes 9:3
This [is] an evil among all [things] that are done under the sun, that [there is] one event unto all,.... A very great evil, a very sore one, the worst of evils. Not an evil, as the providence of God is concerned with it, who does no evil; nor is there any unrighteousness in him; he is righteous in all his ways: but this is an evil, and distressing thing, to the minds of good men; see Psalms 73:2; and is what bad men make an ill use of, to harden themselves in sin, and to despise religion as an unprofitable thing,
yea, also the heart of the sons of men is full of evil: they are naturally full of evil, of all unrighteousness and wickedness, what comes out of them show it; and because the same things happen to good and bad men, and the wicked pass with impunity, and are outwardly happy as others, or more so, their hearts are fully set in them to do evil, Ecclesiastes 8:11;
and madness is in their heart while they live; or "madnesses" x: every sin is madness; for who but a madman would stretch out his hand against God, and strengthen himself against the Almighty, and run upon him? who but a madman would rush into sin in the manner he does, and expose himself to dangers and death, even eternal death? Wicked men are mad upon their lusts, and mad against the saints, and all that is good; this insanity is in their hearts, and shows itself in their lives, and continues with them as long as they live, unless called by grace;
and after that [they go] to the dead; after all the madness of their lives, they die and go into the state of the dead, and are among which refers not so much to the interment of bodies in the grave, as the company with which their separate spirits are; they go not to the righteous dead, but to the wicked; see Proverbs 2:18; so Alshech; they go to the dead; not to the righteous, who, in their death, or when dead are called living, but, as Jarchi observes, at their end they go down to hell. The Targum is,
"after the end of a man, it is reserved for him that he be corrected with the dead, according to the judgment (or desert) of sins.''
x הוללות "insaniae", Montanus, Mercerus, Drusius, Amama, Gejerus, Rambachius; "omnis insania", Junius Tremellius.