十不二門指要鈔 2.123

2.123

初、標。權是九界七方便，實則佛法圓乘，四時未會權實不融，此經開之皆稱祕妙，故云不二。

First, the heading. The expedient refers to the nine realms and the seven expedient means; the real refers to the Buddha Dharma's perfect vehicle. During the four periods, before convergence, the expedient and the real were not fused; this sūtra opens them so that they are all called secret and wondrous. Hence it is said: nondual.