The chapter opens with a line doing a quite different job from the rest of it: the form of great power follows the way and nothing else. That single sentence is the clearest statement in the book of how its two governing terms are related, and it is easy to walk past on the way to the more famous vague and elusive passage.
De, the word usually rendered power or virtue, is not an ethical quality here. It is nearer to what a thing is able to do because of what it is, the efficacy that follows from having a particular nature. Read that way the line says that the efficacy of anything is a function of its conformity to the way, and that it has no second source: not training, not effort, not accumulated merit.
That claim is what makes the whole second half of the book possible. Chapters thirty-eight to eighty-one in the received arrangement are largely about how rulers, generals and sages behave, and every one of them assumes that effectiveness comes from alignment rather than from force. Chapter thirty-eight states it negatively, that the highest power is not powerful and so has power. Chapter fifty-one states it developmentally, that the way gives things life and power rears them.
The placement is one small reason readers have doubted that the eighty-one chapter arrangement preserves any original order. By subject this chapter belongs with the material on power, which the received text does not begin for another seventeen chapters. The division into chapters is an editorial layer, and the manuscripts recovered in the twentieth century do not carry it.