法華論疏 3.120

3.120

第四人者，方便令入涅槃城故。涅槃城者，所謂諸佛禪三昧城故。過彼城已，然後令入大涅槃城故。

"As for the fourth person, it is by skillful means to cause them to enter the city of nirvāṇa. The city of nirvāṇa is the so-called city of the Buddhas' dhyāna-samādhi. It is because after passing beyond that city, he thereafter causes them to enter the city of great nirvāṇa."