All go unto one place; all are of the dust, and all turn to dust again.

Wesley's Notes

3:20 One place - To the earth, out of which they were taken. All turn - All their bodies.

Matthew Henry's Concise Commentary

3:16-22 Without the fear of the Lord, man is but vanity; set that aside, and judges will not use their power well. And there is another Judge that stands before the door. With God there is a time for the redressing of grievances, though as yet we see it not. Solomon seems to express his wish that men might perceive, that by choosing this world as their portion, they brought themselves to a level with the beasts, without being free, as they are, from present vexations and a future account. Both return to the dust from whence they were taken. What little reason have we to be proud of our bodies, or bodily accomplishments! But as none can fully comprehend, so few consider properly, the difference between the rational soul of man, and the spirit or life of the beast. The spirit of man goes upward, to be judged, and is then fixed in an unchangeable state of happiness or misery. It is as certain that the spirit of the beast goes downward to the earth; it perishes at death. Surely their case is lamentable, the height of whose hopes and wishes is, that they may die like beasts. Let our inquiry be, how an eternity of existence may be to us an eternity of enjoyment? To answer this, is the grand design of revelation. Jesus is revealed as the Son of God, and the Hope of sinners.