大方廣佛華嚴經隨疏演義鈔 44.57

44.57

疏「一非為欲惱眾生先須持戒」者，如欲禁龍，曾聞羅漢持戒而能遣龍，遂即持戒是也。

The Commentary states: "First, it is not that for the sake of wishing to torment sentient beings one must first uphold precepts." This is like someone wishing to bind a nāga, who, having heard that an arhat can dispel nāgas by upholding precepts, thereupon upholds the precepts.