《汉书·志·天文志》
二星之间距离相近，其预示的殃祸大，二星距离相远，所示灾害无所伤害，二星相距在观测距离七寸以内必有害伤。
二星相近者其殃大，二星相远者殃无伤也，从七寸以内必之。
When the distance between two stars is close, the misfortune foreshown will be great; when the distance between two stars is far, the calamity is unlikely to cause any harm; when the distance between two stars is within seven cun of the observation distance, there will certainly be harm or injury.