Albert Barnes Commentary Ecclesiastes 2:10

"And whatsoever mine eyes desired I kept not from them; I withheld not my heart from any joy; for my heart rejoiced because of all my labor; and this was my portion from all my labor." — Ecclesiastes 2:10 (ASV)

Portion - A word of frequent occurrence. By it Solomon describes the pleasure found in the act of working and also perhaps the pleasure felt in the process of acquiring wisdom; this pleasure is admitted to be good, if received from God (Ecclesiastes 2:26; Ecclesiastes 5:18; compare 1 Timothy 4:4); but being transitory it is subject to vanity, and therefore does not afford a sufficient answer to the repeated question, “What profit etc.?” (Ecclesiastes 1:3).