淨名經集解關中疏 2.259

2.259

The Bodhisattva Sumati said, "Saṃsāra and nirvāṇa constitute duality. If one sees the nature of saṃsāra, then there is no saṃsāra, neither bondage nor liberation, neither burning nor extinction. One who understands in this way enters the dharma gate of non-duality."
Receiving future existence is saṃsāra; the complete extinction of future existence is nirvāṇa. Realizing that the saṃsāra of the world is delusion means there is no saṃsāra. Sengzhao says, "Bondage and burning are saṃsāra; liberation and extinction are alternative names for nirvāṇa."