The five colours blind the eye.
The five tones deafen the ear.
The five flavours cloy the palate.
Racing and hunting madden the mind.
Rare goods tempt men to do wrong.
Therefore, the Sage takes care of the belly, not the eye.
He prefers what is within to what is without.
This is one of those times that I am grateful for the internet. When I read this passage, the general theme was obvious enough—do not focus all your energy on material gains, but instead, seek within for spiritual treasures. But I knew I was missing something critical and that something must be associated with the number five, which is echoed in the first three lines. From my western perspective, I could not think of any significance that the number five would have in the context of this passage. So I resorted to Google.
I learned that in Chinese thought, the number five is significant because the Chinese believe there are five elements: Earth, Water, Wind, Fire, and Metal. From my western perspective, I have always considered there to be four elements: Earth, Water, Wind, Fire. Now the meaning of the first few lines made sense. It is the distraction of the elements to our physical senses that draws our focus away from the internal and towards the external.
This is an example of how ideas and symbols can be interpreted differently based upon the cultural context. Whenever we attempt to uncover the meaning of something, we should always consider the context in which it was created.