Rather than saying, "All work is vanity,"Solomon made the same point by asking this rhetorical question that expects a negative response. He used this literary device often throughout the book (cf. 2:2; 3:9; 6:8, 11-12; et al.).
"Advantage"(Heb. yitron) refers to what remains in the sense of a net profit. Solomon was not saying there is nothing good about work or that it is worse than being unemployed. He only meant that all the work a person may engage in does not yield really long-term profit even though it may yield short-term profit including financial security (cf. Mark 8:36).19
"Under the sun,"used 29 times in Ecclesiastes and nowhere else in the Old Testament, simply means "on the earth,"that is, in terms of human existence (1:9, 14; 2:11, 17, 18, 19, 20, 22; 3:16; 4:1, 3, 7, 15; 5:13, 18; 6:1, 5, 12; 8:9, 15, 17; 9:3, 6, 9, 11, 13; 10:5; cf. 1:13; 2:3; 3:1). The phrase shows that the writer's perspective was universal, not limited to his own people and land.20
"You think you have all the dishes washed and from a bedroom or a bathroom there appears, as from a ghost, another dirty glass. And even when all the dishes are washed, it is only a few hours until they demand washing again. So much of our work is cyclical, and so much of it futile."21