Midrash Rabbah - Ecclesiastes 5:20

“As he came forth of his mother‘s womb, [naked shall he go back as he came, and shall take nothing for his labour.]" (Ecclesiastes 5:14). Genibah said: It is like a fox who found a vineyard which was fenced in on all sides. There was one hole through which he wanted to enter, but he was unable to do so. What did he do? He fasted for three days until he became lean and frail, and so got through the hole. Then he ate [of the grapes] and became fat again, so that when he wished to go out he could not pass through at all. He again fasted another three days until he became lean and frail, returning to his former condition, and went out. When he was outside, he turned his face and gazing at the vineyard, said, 'O vineyard, O vineyard, how good are you and the fruits inside! All that is inside is beautiful and commendable, but what enjoyment has one from you? As one enters you so he comes out.’ Such is this world... R. Meir: When a person enters the world his hands are clenched as though to say, ‘The whole world is mine, I shall inherit it’; but when he takes leave of it his hands are spread open as though to say, ' I have inherited nothing from the world.’ For thus said Solomon, “As he came forth of his mother‘s womb, naked shall he go back as he came, and shall take nothing for his labour." (Ecclesiastes 5:14) [Soncino Translation]