大般涅槃經義記 7.109

7.109

下正答中，對問唯二，文別有三：一述成向前第二難中闡提不定、二「如汝言」下正答初難、三「犯四重」下答其後難。問曰：闡提不定之義依問未至，何故先述？解言：先明闡提不定，能得菩提，顯後所釋一闡提人佛性不斷，義便故爾。

Below, in the direct answer, there are only two with respect to the questions, but the text is divided into three parts: first, affirming the indeterminacy of the icchantika in the second challenge above; second, from "As you say" onward, directly answering the first challenge; third, from "Committing the four major offenses" onward, answering his later challenge. Question: The meaning of the icchantika's indeterminacy had not yet been reached according to the question; why affirm it first? Explanation: First explaining that the icchantika is indeterminate and able to attain bodhi reveals what is explained later—that an icchantika's buddha-nature is unbroken; it is done because it is methodologically convenient.