"a large amount." It is understood that this refer to profit gained. Alternate translation: "two handfuls of profit" or "a large amount of profit" (See: [[rc://en/ta/man/translate/figs-ellipsis]])
The author speaks of everything that people do as being useless as if they were trying to control the wind. See how you translated a similar phrase in [Ecclesiastes 1:14](../01/14.md). Alternate translation: "that is as useless as trying to control the wind" (See: [[rc://en/ta/man/translate/figs-metaphor]])