瑜伽論記 5.191

5.191

八解脫中，淨不淨非二色第一捨勝解，是名第三者，由淨解脫有三種想：一、展轉相待；二、展轉相入，此二通觀淨不淨色，平等觀故名捨勝解；三、展轉一味想，唯觀光明不作淨不淨名非二色，第一捨勝平等觀光明最勝位故名第一捨。

Among the eight liberations, "supreme equanimous resolute aspiration toward pure, impure, and neither-form is called the third": this is because the pure liberation involves three kinds of ideations: first, mutual relativity; second, mutual penetration—these two generally contemplate pure and impure form, and because they contemplate them with equanimity, this is called "resolute aspiration of equanimity"; third, the ideation of mutual single-flavor, which contemplates only light without positing pure or impure, hence called "neither-form." Since the supreme equanimity of resolute aspiration contemplates light in its most supreme state, it is called the "foremost equanimity."