大方廣佛華嚴經隨疏演義鈔 42.21

42.21

疏「有去不留空」者，明空有無二，故有即是空。若去於有，即以去空。若有去存空，則空有為二故。

Regarding the commentary's statement, "When existence is removed, emptiness does not remain": This clarifies that emptiness and existence are non-dual; thus existence is itself emptiness. If existence is removed, emptiness is thereby removed. If existence were removed and emptiness remained, then emptiness and existence would be dual.