大毘盧遮那經阿闍梨真實智品中阿闍梨住阿字觀門 1.18

1.18

When the practitioner achieves correspondence in this manner, distributing the syllables and reciting mantras, their body is the body of the Vidyādhara, identical and without difference to the empowerment of Mahāvairocana Tathāgata's divine power. This wheel is also named the wheel of causes and conditions; when master, disciple, and maṇḍala all have the syllables arranged in this way, it is also named the secret wheel; these syllables are also the syllables of all Buddha-minds, and it is also named the wheel of mantras.