大乘義章 1.127

1.127

次就真諦以別三門。於中有四：一遣生死涅槃之相以別三門、二遣三世差別之相以別三門、三就空理總別之義以別三門、四就實性有無之義以別三門。言遣生死涅槃相者，如論中說「觀察生死涅槃皆空，名之為如。」

Next is distinguishing the three portals solely in terms of the ultimate truth. Within this there are four: 1. Distinguishing the three portals by dispelling the characteristics of saṃsāra and nirvāṇa; 2. Distinguishing the three portals by dispelling the differentiated characteristics of the three times; 3. Distinguishing the three portals in terms of the general and specific meanings of the principle of emptiness; 4. Distinguishing the three portals in terms of the existence and non-existence of the real nature. Regarding dispelling the characteristics of saṃsāra and nirvāṇa, as stated in the treatise: 'Contemplating that saṃsāra and nirvāṇa are both empty is called tathatā.'