大毘盧遮那成佛經疏 2.42

2.42

第十三「云何諍心？謂於自己而生是非」者，謂內懷是非之心，如自思惟一義竟，輒復自設異端推求其失。雖善心諮受於人，既領受已，還自推求得失，謂此事合爾、此不合。多有如是相現，當知是諍心也。

Thirteenth: regarding "What is the disputatious mind? It means giving rise to right and wrong within oneself": this means harbouring a mind of right and wrong within oneself. For instance, after reflecting on a meaning by oneself, one immediately sets up differing alternatives on one's own to investigate its flaws. Although one consults and receives [teachings] from others with a wholesome mind, having accepted them, one turns back to investigate gain and loss oneself, saying, "This matter is fitting; this is not fitting." When such marks appear frequently, one should know that it is the disputatious mind.