Genesis 3:19
17 But to Adam he said, “Because you obeyed the voice of52 your wife and ate from the tree about which I commanded you, ‘You must not eat from it,’ the ground is cursed because of you; in painful toil you will eat of it all the days of your life. 18 It will produce thorns and thistles for you, but you will eat the grain of the field. 19 By the sweat of your brow you will eat food until you return to the ground, for out of it you were taken; for you are dust, and to dust you will return.” 20 The man named his wife Eve, because she was the mother of all the living. 21 The Lord God made garments from skin for Adam and his wife, and clothed them.
Ecclesiastes 3:20
18 I also thought to myself, “It is for the sake of people, so God can clearly show them that they are like animals. 19 For the fate of humans and the fate of animals are the same: As one dies, so dies the other; both have the same breath. There is no advantage for humans over animals, for both are fleeting. 20 Both go to the same place; both come from the dust, and to dust both return. 21 Who really knows if the human spirit ascends upward, and the animal’s spirit descends into the earth?” 22 So I perceived there is nothing better than for people to enjoy their work because that is their reward; for who can show them what the future holds?
Notes and References
"... If we take Genesis 3:19 and Ecclesiastes 3:20, the first stage would be to identify whether “dust to dust” is a citation; the second whether its potential source is Genesis and whether Genesis was known to Qohelet’s audience; third, to identify thematic connections such as mortality and human origins which are important issues in both texts. The last stage would be to analyse other thematic elements in Genesis that might help us to establish a cognitive environment that enables us to arrive at a richer understanding of Ecclesiastes. As noted above, the diverse books of the Bible cite other biblical books in a variety of ways. It was also noted that establishing the existence of the citation, allusion or echo must be done with care. It will be argued below that Ecclesiastes reuses the language of Genesis 3 and 4 for its own ends. Lexicographic citations, the use of common words, are among the most difficult to substantiate and the reuse of relatively common words is insufficient to demonstrate dependency, though clusters of common language, such as we find in Ecclesiastes and Genesis, may be sufficient to demonstrate a link ..."
Moxham, Ray Qohelet's Fall: The Use of Genesis 2-4 in the Book of Ecclesiastes (pp. 35-36) University of Otago, New Zealand, 2015