大般涅槃經義記 6.107

6.107

自下第二明佛化意，為使眾生得第一義說前世諦。於中四句：一明向前所說世諦若於如來即第一義；二「何以」下釋，如來為顯第一義諦宣說世諦，故即第一；三「亦令」下明為第一說世諦意，為使眾生得第一義，故為第一宣說世諦，先順後反；四「如來有時演說世」下辯明如來化意難測。「如來說世，眾生謂佛說第一」者，如佛昔說苦集滅道，小乘眾生取為真諦。「有說第一，眾生謂佛說世諦」者，如說佛性為陰界入、十二緣等，眾生便謂同己所解，取為世諦。下結難解，「此唯佛境，非二乘知」，為此語者，欲使眾生於向異說不應定執取為世諦，佛意皆為顯第一義。

From here below, the second part clarifies the Buddha's intention in transforming, which is that he speaks the aforementioned conventional truths in order to cause sentient beings to attain the ultimate truth. Within this there are four clauses: First, clarifying that the conventional truths spoken previously, if in relation to the Tathāgata, are immediately the ultimate truth. Second, the explanation from "why" onward: because the Tathāgata speaks conventional truths to reveal the ultimate truth, they are immediately the ultimate. Third, from "also causing" onward, clarifying the intention of speaking conventional truths for the sake of the ultimate: in order to cause sentient beings to attain the ultimate truth, he speaks conventional truths for the sake of the ultimate, first following and then reversing. Fourth, from "the Tathāgata sometimes expounds the conventional" onward, explaining that the Tathāgata's intention in transforming is difficult to fathom. "When the Tathāgata speaks of the conventional, sentient beings think the Buddha speaks of the ultimate": as when the Buddha formerly spoke of suffering, accumulation, cessation, and the path, and small-vehicle sentient beings grasped them as true reality. "When speaking of the ultimate, sentient beings think the Buddha speaks of conventional truth": as when speaking of buddha-nature as the aggregates, realms, sense fields, twelve links of dependent origination, and so forth, sentient beings then think it is identical to their own understanding and grasp it as conventional truth. Below, it concludes that it is difficult to understand: "this is exclusively the realm of the Buddha, not known by the two vehicles." Speaking these words is intended to ensure that sentient beings do not rigidly cling to the different teachings mentioned above as conventional truths; the Buddha's intention is entirely to reveal the ultimate truth.