Book 6: 《雍也》 Yong Ye (There is Yong)
《雍也》 Passage 6.21
子曰：「中人以上，可以語上也；中人以下，不可以語上也。」
Legge Translation (1861)
The Master said: "To those whose talents are above mediocrity, the highest subjects may be announced. To those who are below mediocrity, the highest subjects may not be announced."