《史记·十二本纪·秦始皇本纪》
仙方中要求，君主时时隐蔽行迹。来躲避恶鬼，躲避了恶鬼，真人就来到了。
方中，人主时为微行以辟恶鬼，恶鬼辟，真人至。
The prescription for the elixir of immortality requires the monarch to frequently hide his whereabouts, to avoid evil spirits. If evil spirits are avoided, the real person will come.