Nine

Filling a cup to the brim is not as good as stopping at the right moment.
Sharpen and hammer a blade, but still its edge will not last long.
Fill your house with treasure and you'll worry about guarding it.

Wealth, status, and pride: they contain within themselves the seeds of your downfall.

Do your work and step back: that is Heaven's Way.

Commentary:
The first three lines are variations on each other, and their syntax is parallel in the original Chinese. All three describe moderation, but they deal with different facets of it. The first line emphasizes that in most things, what we want is not one extreme or the other, but something in the middle. The second uses a sharp blade as an example of an unnatural and fragile situation, which needs very little to upset it. This is interesting, because many translators have something like this: "Over-sharpen a blade and its edge will be lost," implying that a sharp blade is a good thing and you need to be careful if you want to maintain one. However, in the original Chinese sentence there is no character that means "over-" or "too much." The gloss is something like [sharpen and hammer it, not can long preserve]. A translation that's closer to this gloss also fits much more with the rest of the Tao Te Ching; sharpness, whether in a blade or in a person, is always something that is discouraged.

I'm still ambivalent about using the word "Heaven" in my translation of the Tao Te Ching, even though it's virtually ubiquitous in other translations. The Chinese character does refer to the sky, but as can be seen from this and many other passages, it's used as a kind of synonym for "ideally natural." Think of the flowing water that the authors of the Tao Te Ching admire so much; but imagine that in a higher, ideal reality there were a kind of "super-water" that surpasses real water in every quality the TTC authors admire: it flows more easily, it struggles less against obstacles, etc. This is the kind of meaning the authors are using "Heaven's Way" for.