'Weight' in the Bible

What does a man get for all his work, and for the weight of care with which he has done his work under the sun?

And he is in fear of that which is high, and danger is in the road, and the tree is white with flower, and the least thing is a weight, and desire is at an end, because man goes to his last resting-place, and those who are sorrowing are in the streets;