大毘盧遮那經供養次第法疏 2.21

2.21

第七段中有頌真言印。證最勝菩提者，能修行者所得果也。如來座真言門。阿是障，傍有二點即是除遣，此即除蓋障義也，以此為座畢竟不起一切障故。何故？阿字是障，阿字能除障也。

The seventh passage contains verses, mantras, and mudrās. "Realizing supreme bodhi" is the fruit obtained by the practitioner. Section on the Tathāgata Throne Mantra. A is obstacle; having two dots beside it means elimination; this is the meaning of removing the covering of obstacles (Sarvanīvaraṇaviṣkambhin), because taking this as the seat, all obstacles ultimately do not arise. Why? The letter A is obstacles, and the letter A can eliminate obstacles.