四分律比丘含注戒本 2.165

2.165

佛在拘睒毘。闡陀起屋，蟲水和泥，教人和，長者見嫌：「無有正法，害眾生命！」比丘舉過，佛因制戒。

(The Buddha was in Kauśāmbī. Channa was erecting a building and mixed mud with water containing living creatures, and instructed others to mix it. An elder saw this and expressed disapproval: “This is not the true Dharma, harming the lives of sentient beings!” The bhikṣus reported the offense, and the Buddha formulated the precept on this basis.)