《史记·三十世家·孔子世家》
过了些时候，师襄子说： 已经领悟了曲子中表达的思想，可以多学些内容了。 
有间，曰： 已习其志，可以益矣。 
After a while, Shi Xiang Zi said, "You have already understood the thoughts and emotions expressed in the song, and you can learn more now."