Jamieson, Fausset and Brown on Ecclesiastes 11:10

10. sorrow--that is, the lusts that end in "sorrow," opposed to "rejoice," and "heart cheer thee" (Ec 11:9), Margin, "anger," that is, all "ways of thine heart"; "remove," &c., is thus opposed to "walk in," &c. (Ec 11:9).

flesh--the bodily organ by which the sensual thoughts of the "heart" are embodied in acts.

childhood--rather, "boyhood"; the same Hebrew word as the first, "youth" in Ec 11:9. A motive for self-restraint; the time is coming when the vigor of youth on which thou reliest, will seem vain, except in so far as it has been given to God (Ec 12:1).

youth--literally, the dawn of thy days.