大方廣佛華嚴經隨疏演義鈔 64.27

64.27

疏「二就行分別」等者，此約生起名生。七地頓起，何名無生？以起行皆遍，無可新起，故云無生耳。

On the commentary passage "Second, discriminating in terms of practice" and so forth: this designates arising in terms of being generated. On the seventh bhūmi it arises all at once; why is it called non-arising? Because the practices that are generated are completely pervasive, and there is nothing new to generate; hence it is merely called "non-arising".