《后汉书·本纪·孝安帝纪》
秋七月初四，诏令说： 从前的帝王，秉承天命治理人民，没有不掌握天文仪器，了了解日月五星变化的，我以薄德之身，总理一国大业，阴阳不调，变异时见，万民饥寒流离，羌貊叛逆。
秋七月戊辰，诏曰： 昔在帝王，承天理民，莫不据璇机玉衡，以齐七政。朕以不德，遵奉大业，而阴阳差越，变异并见，万民饥流，羌貊叛戾。
On July 4th of Autumn, an imperial edict was issued, which said: In ancient times, the emperors, following the mandate of Heaven, ruled the people. None lacked an understanding of astronomical instruments, nor did they fail to understand the changes in the sun, moon, and five planets. I am of low virtue and have taken charge of the great cause of the state. However, the Yin and Yang are not in harmony, and strange phenomena are constantly appearing. The people are hungry, cold, and homeless. The wild tribes of Qiang and Mo are rebelling.