肇論新疏 3.316

3.316

虛無、重玄，擬老書為文，謂涅槃也。有涯之數令智辨之人尚不闚其畔，無涯之真使三乘眾生欲令頓盡，豈能爾耶？譬乎九層之臺不可躐等，萬里青冥頓欲階升，於道未許故。

“The void” and “twofold mystery” adapt phrases from the Daoist text to refer to nirvāṇa. When bounded phenomena cause even people of wisdom and eloquence to fail to peer into their borders, how could the boundless truth be suddenly exhausted by sentient beings of the three vehicles, if they wish it so? It is like a nine-storied terrace where steps cannot be skipped; to wish to ascend at once to the azure skies of ten thousand miles is not permitted by the Dao.