The middle of the chapter describes a ceremony and then says what would be better than it. At the enthronement of an emperor or the installation of the three ministers, better than sending in a jade disc ahead of four horses is to sit and offer this way.
The detail is precise court protocol. A jade disc was among the most valuable ritual gifts available, and presenting one carried before a team of horses was the form a great gift took at a great occasion. The chapter is not inventing an image; it is naming the most expensive thing a person could put in front of a new sovereign.
Against that it sets an offering that costs nothing and requires no ceremony, and the verb it uses is simply to sit and present. What is being proposed is that a doctrine be handed over at the moment when tribute is expected.
That tells us something about the setting the chapter imagines for itself. This is a book that expects to be given to rulers at the beginning of reigns, and it says so. The framing recurs elsewhere, in chapter twenty-six with its lord of ten thousand chariots, in chapter sixty with its large state, and in chapter seventy-eight with the titles a ruler earns by taking on the state's filth.
The closing question is defensive in a way the book seldom is. Why did the ancients value it? Was it not said that by it the seeker obtains and the guilty escape? The chapter appeals to what was formerly said rather than arguing, and the two benefits it names are getting what you are after and getting out of trouble, which are the plainest terms it could have chosen.