維摩經玄疏 6.65

6.65

一、明三藏四門、通教四門同入偏真之理者，各因四門，同見第一義，得二種涅槃，是同也；理雖是一，而門有異者，既有巧、拙兩度之殊，故有兩種四門能通之別也。真理無二，故所通至體是一也。譬如州城開四門，使君是一；而從四門入者，門雖有殊，而所見使君祇是一也。三藏教四門，如從州城四邊偏門而入；通教四門，如從四正門而入。偏正雖殊，入見偏真第一義諦，得二種涅槃是一也。

First, explaining that the four doors of the Tripiṭaka teaching and the four doors of the shared teaching together enter the principle of partial truth: through their respective four doors, [practitioners of both teachings] equally perceive the primary truth and attain the two kinds of nirvāṇa; in this they are identical. Although the principle is one, the doors are distinct: since there is the difference between the skillful and crude crossings, there is the distinction between the two kinds of four doors that can provide access. Because the true principle is non-dual, the substance to which access is gained is one. For example, a prefectural city opens four gates, but the governor is only one; although those who enter from the four gates take distinct gates, the governor they see is merely one. The four doors of the Tripiṭaka teaching are like entering from the four side gates of the prefectural city; the four doors of the shared teaching are like entering from the four main gates. Although the side and main [gates] differ, entering to perceive the partial truth of paramārtha-satya and attaining the two kinds of nirvāṇa are identical.