《论衡·卷二十四·卜筮篇》
周武王生病，周公用龟甲占卜了三次，周公说： 所遇到的都是吉兆。 
周武王不豫，周公卜三龟。公曰： 乃逢是吉。 
When King Wu of Zhou was ill, the Duke of Zhou divined three times with tortoise shells and said: "All the omens I have encountered are auspicious."