肇論新疏 3.69

3.69

九折之一也。覈，考覈也。因前說涅槃之體非有非無，故今折之，體竟何在？此假二乘有無之問，以破其執。

This is the first of the nine rejoinders. He means to investigate and examine. Because it was previously stated that the essence of nirvāṇa is neither existent nor non-existent, he now breaks it down: where after all does the essence reside? This posits the questions of existence and non-existence of the two vehicles to shatter their attachments.