Shared ground
These lines press a basic question: if life is made up of changing “times,” what lasting “profit” is left over from human labor (v.9). The speaker does not deny that work matters or that effort is real. He questions whether work can finally produce a surplus that remains secure.
The passage also holds two statements together about God’s role. First, human life includes a heavy “burden” that God has “given” to humanity, and it is experienced as something people are “afflicted with” (v.10). Second, God “makes everything beautiful” (that is, fitting/appropriate) “in its time” (v.11). So the text combines burden and order, not one without the other.
Finally, the speaker says God has set “eternity” in human hearts while humans still cannot “find out” the whole scope of God’s work “from the beginning even to the end” (v.11). The human condition includes both a sense that there is a bigger whole and a real limit on grasping it.
Where interpretation differs
1) What “profit” means (v.9). Some read “profit” mainly as lasting advantage—what remains after the work is done and time has passed. Others take it more narrowly as material surplus or measurable gain. Either way, the question is skeptical about labor’s ability to secure something permanent.
2) What “beautiful” means (v.11). Some take it to mean “pleasant” or emotionally satisfying. Others argue it means “fitting” or “appropriate,” focusing on timing rather than immediate enjoyment. The second reading fits the surrounding focus on seasons and limits.
3) What “eternity in their hearts” refers to (v.11). Some understand it as an inner longing for the everlasting, or awareness that life is more than the present moment. Others take it as a sense of “the whole picture” (a desire to understand how everything fits together) that remains unfulfilled.
Why the disagreement exists
The key terms are compact and flexible: “profit” can be financial or broader; “beautiful” can describe attractiveness or suitability; “eternity” can mean endless time, a sense of the world as a whole, or an awareness of something beyond the immediate moment. Verse 11 also pairs two ideas—human hunger to know and human inability to know—so interpreters differ on which side is emphasized.
What this passage clearly contributes
Explicitly, the passage claims: (1) labor raises the question of whether anything lasting is gained (v.9); (2) the human burden is not accidental but “given” and experienced as affliction (v.10); (3) God’s timing makes things “beautiful/fitting” in their proper season (v.11); (4) humans have an “eternity” sense, yet cannot trace God’s total work from start to finish (v.11). Theologically inferred (but consistent with the text) is a tension: humans live inside time, sense more than time, and still lack comprehensive access to God’s full plan.