The chapter opens with a mechanical image and gets a redistributive argument out of it. The way of heaven is like the drawing of a bow: the high is pressed down and the low is raised up, what has too much is reduced and what has too little is supplemented.
The image is exact and worth visualising. Bringing a bow to full draw means the two limbs move toward each other, the upper coming down and the lower coming up, and the string that was slack is taken in. Nothing is added from outside. The tension is produced entirely by the reduction of one part and the extension of another, and the result is a weapon that works.
From that the chapter states the rule twice, once for heaven and once against human practice. The way of heaven reduces what has too much and supplements what has too little. The way of man is not like this, and reduces what has too little in order to serve what has too much.
That second sentence is the flattest statement of inequality in the book and it is offered as an observation, not as an accusation. Human arrangements move resources upward, and the chapter says so as a matter of how things are done.
The question that follows is the practical one. Who is able to have too much and offer it to the world? The answer given is only one who has the way, which makes the redistribution voluntary and rare rather than a policy anybody could institute.