大方廣佛華嚴經隨疏演義鈔 74.17

74.17

疏「二約雙顯」者，謂上但顯實，則唯性而非相；今性相皆具，故云雙顯。謂由體一故非異，相差別故非不異，此舉雙是以顯雙非。

As for the commentary's "second, in terms of mutual manifestation": above it merely revealed the real, which was solely nature and not marks; now, possessing both nature and marks, it is called mutual manifestation. It means that because the essence is one, it is not different; because the marks are differentiated, it is not not different. This adduces both affirmations to reveal both negations.