大毘盧遮那經阿闍梨真實智品中阿闍梨住阿字觀門 1.15

1.15

Therefore, speaking generally, the spontaneous mutual entry is also explained as divided into three parts: the head is the first part (yellow); the throat and heart are the middle part (white); and the navel is the final part (black). If one uses the syllable *ka* as the wheel, one does not use the syllable *kha*; if one uses the syllable *kha* as the wheel, one does not use the syllable *ka*. This is called the arising of the bodhicitta, with practice and fruit as the middle, and great stillness as the end; these are named the three parts. After the *ācārya* has thus formed the body through the three tiers, they also distribute them in this way onto the maṇḍala and the disciple; when the three matters are all completed, this is named the secret maṇḍala. If one does not thoroughly comprehend the intended meaning here, it is difficult to proceed based on the external ritual; it cannot be called well performed, the effort is spent in vain, and nothing will be accomplished.