華嚴經探玄記 1.38

1.38

五護身法師等立五宗教，謂此於前第四宗內，開真佛性以為真宗，即《涅槃》等經；第五名法界宗，即《華嚴》，明法界自在無礙法門。

Fifth, Dharma Master Hushen and others established five doctrinal schools: within the aforementioned fourth school, they separated true Buddha-nature to make it the school of reality, namely the Mahāparinirvāṇa and other sūtras; the fifth was named the dharmadhātu school, namely the Avataṃsaka, clarifying the autonomous and unobstructed doctrinal gate of the dharmadhātu.