大方廣佛華嚴經隨疏演義鈔 18.41

18.41

疏「妙觀察智觀察平等」者，論云「謂此心品善觀諸法自相共相無礙而轉，攝觀無量總持定門，及所發生功德珍寶，能現無邊作用差別皆得自在，雨大法雨、斷一切疑，令諸有情皆獲利樂。」既云善觀諸法自相共相無礙而轉，此即明平等能遍觀一切諸法，故云觀察平等。

On the commentary's "the wondrous contemplation cognition contemplates equality": the treatise states, "This mental associate is skilled at contemplating the specific characteristics and common characteristics of all phenomena, operating without obstruction; it encompasses and contemplates limitless dhāraṇīs and gates of concentration, as well as the treasures of virtue generated [thereby]; it is able to manifest limitless distinctions of functioning, all attaining mastery; it rains down the rain of the great Dharma, cuts off all doubts, and causes all sentient beings to obtain benefit and joy." Since it says that it is skilled at contemplating the specific characteristics and common characteristics of all phenomena, operating without obstruction, this clarifies that equality can pervasively contemplate all phenomena; hence it says, "contemplates equality."