瑜伽論記 2.403

2.403

殺生成業道究竟者，所殺者命斷已方成，非正死、有俱死、前死及自殺非業道故，不爾便應皆成業道，第三句害極害執者，次有三故。

Regarding killing living beings culminating in a course of karma: it is accomplished only after the life of the one killed has been severed; [the victim] in the process of dying, simultaneous death, dying beforehand, and killing oneself are not courses of karma, for otherwise all would constitute courses of karma. The third phrase, "harm, extreme harm, and adherence," is because there are three following.