華嚴經探玄記 17.34.4

17.34.4

後二此淨法，一性淨、二斷淨。 並由法力成此等行，故名攝持。 上來總三百二十門明因圓究竟訖。

the last two are these pure dharmas: 1. purity of nature, 2. purity through eradication. All these practices are accomplished through the power of the Dharma; hence it is called 'sustainment'. The above total of three hundred and twenty gates explaining the perfection and culmination of causal practice is concluded.