《礼记·月令》
这个月，命令太卜用牲血涂抹龟甲着草，通过审视兆象卦象来判断吉凶，考察是否有阿谈拍马结党营私的人，使他们的罪行无法掩蔽。
是月也，命大史衅龟策，占兆审卦吉凶，是察阿党，则罪无有掩蔽。
In this month, the Grand Diviner is instructed to smear turtle shells with animal blood and then divine good or bad fortune by examining the resulting signs and omens; to investigate whether there are people flattering and forming factions in order to pursue private interests and profit, thus exposing their hidden crimes.