Charles Ellicott Commentary Ecclesiastes 1:3

"What profit hath man of all his labor wherein he laboreth under the sun?" — Ecclesiastes 1:3 (ASV)

What profit.— The Hebrew word occurs ten times in this book (Ecclesiastes 2:11; Ecclesiastes 2:13; Ecclesiastes 3:9; Ecclesiastes 5:9; Ecclesiastes 5:16; Ecclesiastes 7:12; Ecclesiastes 10:10–11) and nowhere else in the Old Testament, but is common in post-Biblical Hebrew. The frequently recurring phrase “under the sun” is a peculiarity of this book. In other books we have “under heaven.”