《后汉书·列传·蔡邕列传下》
去年六月二十八日，太白星与月亮相迫，对兵事不利。鲜卑侵犯边境，自远地来，现在出师征讨，没有取得什么进展。上违反了天文，下不顺于人事。
故当其有事也，则蓑笠并载，擐甲扬锋，不给于务。
On June 28 last year, the planet Venus was near the moon, which was not good for military affairs. The Xianbei invaded the border, coming from a distant land, and now that we have sent troops to defeat them, we have not made any progress. This violates the laws of astronomy above and does not comply with human affairs below.