佛遺教經論疏節要 1.161

1.161

持戒去惑如鉤出蛇，此言定共戒也。論云「禪定相應心戒故」。《四分律》云「云何為學？為調三毒故。」蛇出安眠者，上句明斷惑，下句明已辦。總而示之，以戒外防、以定內靜，故能發慧斷惑也。若乃外衒持相、內無定慧，我慢自高戒取斯起，更引黑蚖以歸心室，不知其可也。智者思之誡之。

Upholding the precepts to remove delusions is like using a hook to extract a snake; this refers to the precept concomitant with dhyāna. The treatise says: "Because it is the mind-precept corresponding to dhyāna-concentration." The Sifen lü says: "What is meant by training? It is for the sake of taming the three poisons." The snake departing and sleeping peacefully: the upper phrase clarifies severing delusion, and the lower phrase clarifies the task being accomplished. Showing it comprehensively: with precepts guarding externally and with concentration stilling internally, one is therefore able to generate wisdom and sever delusion. If one merely flaunts the outward forms of upholding while internally lacking concentration and wisdom, arrogance elevates oneself and attachment to wrongful precepts arises, thereby inviting the black viper back into the chamber of the mind; one would not know how that could be permissible. The wise should ponder and take warning from this.