俱舍論頌疏論本 17.52

17.52

中有二三四者，中謂不善，在善、無記中間，故名中也。不善業以善法為二果，以不善法為三果，以無記法為四果。言二果者，謂士用、增上。言三果者，除異熟及離繫。言四果者，唯除離繫。問：「無記與不善如何為等流？」答：「謂遍行不善及見苦所斷餘不善業為同類因，以身、邊見有覆無記為等流果。」

Regarding "the middle has two, three, four": "the middle" refers to unwholesome, because it stands between the wholesome and indeterminate; thus it is called "middle". Unwholesome karma takes wholesome phenomena as two fruits, unwholesome phenomena as three fruits, and indeterminate phenomena as four fruits. The words "two fruits" refer to personal endeavor and sovereignty. The words "three fruits" exclude ripening and disconnection. The words "four fruits" exclude only disconnection. Question: "How can the indeterminate be an outflow of the unwholesome?" Answer: "Universal unwholesome [defilements] and the remaining unwholesome karmas abandoned by seeing the noble truth of suffering act as similar cause, taking the defiled indeterminate view of self and extreme views as outflow fruit."