大方廣佛華嚴經隨疏演義鈔 62.75

62.75

疏「心即是定」者，謂專心已生未生惡、已生未生善，守護即名為心。此是加行，得心一境性，故名為定。《雜集》云「心三摩地者，謂由先修定力，觸心一境性。所以者何？由於前生數修定力，令彼種子功能增長。由種子力，令心任運於三摩地隨順轉變，由此速證心一境性。」釋曰：此明由昔種子，其心任運趣定，即是加行。亦有經論名為念定，繫意住故，故能守境。

Regarding the Commentary's statement: "Mind is precisely absorption": this means that focusing the mind on arisen and unarisen unwholesome states and arisen and unarisen wholesome states, and guarding them, is named "mind." This is the preliminary application that attains one-pointedness of mind; hence it is named absorption. The Abhidharmasamuccaya-vyākhyā states: "Samādhi of the mind means that through the power of previously cultivating absorption, one touches one-pointedness of mind. Why is this? Because through the power of repeatedly cultivating absorption in previous lives, the function of those seeds increases. Through the power of the seeds, the mind spontaneously conforms and transforms toward samādhi, and thereby one swiftly realizes one-pointedness of mind." The explanation is: this clarifies that due to past seeds, one's mind spontaneously tends toward absorption, which is preliminary application. Sūtras and treatises also name it the absorption of mindfulness, because tying the mind makes it abide, and hence it can guard the cognitive object.