For in much wisdom is much grief; and he who increases knowledge increases sorrow.

The sleep of a laboring man is sweet, whether he eats little or much; but the abundance of the rich will not allow him to sleep.

then I saw all the work of God, that man can't find out the work that is done under the sun, because however much a man labors to seek it out, yet he won't find it. Yes even though a wise man thinks he can comprehend it, he won't be able to find it.

Wisdom is better than weapons of war; but one sinner destroys much good.

Furthermore, my son, be admonished: of making many books there is no end; and much study is a weariness of the flesh.