Translation - Analects of Confucius 2.2 There are 300 Odes.

子曰：「詩三百，一言以蔽之，曰『思無邪』。」 Zǐ yuē: Shī sān bǎi, yī yǎn yǐ bì zhī, yuē "sī wú xié."

The master said: There are three hundred Odes, but one sentence may cover them all: "Think not (what is) wicked!"

Notes: this is another good example for the central role of moral psychology in classical Chinese thought, and a particularly good example on the relationship between self-cultivation and understanding in the analects. Confucius never intends the rituals to be performed for their own sake [1]; Confucius, in fact, explicitly criticizes those who merely memorize official documents [2] or practice from rote memory without understanding the circumstances or who practice ritual without an eye toward benevolence [3]. In fact, benevolence in general is the goal for Confucius: this requires both understanding the rituals and the circumstances, but surpasses merely correctly applying ritual to circumstances. The application of ritual may be beneficial, but is by itself insufficient. 

In this sense, the Odes may provide guidelines for action, but they also help the sage engage in the kinds of emotional imagination and activity necessary for beginning to understand emotional interactions with others.

Confucius' instruction here particularly points to the concern with habit, and how our habits (rituals) create habitual modes of thinking. Again, Confucius' concern here is with cultivating the heart-mind. 

[1] don't be a vessel
[2] don't be merely an officious scribe
[3] the goal of the sage is benevolence