'Weariness' in the Bible

All things are full of weariness; man cannot utter it : the eye is not satisfied with seeing, nor the ear filled with hearing.

The work of the foolish will be a weariness to him, because he has no knowledge of the way to the town.

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