大毘盧遮那成佛經疏 16.6

16.6

When the sūtra says "emanate," it means that when a person thoroughly understands this secret teaching, all mundane and supramundane altars emanate from within it, and can be understood in accordance with their respective meanings. There are briefly four kinds of methods for creating the secret, namely: ritual actions (which are the various ritual actions from beginning to end that should be performed in connection with the altar), form (meaning the shapes, marks, and bodily divisions of the principal deities and others), siddhi (meaning the results accomplished), and placement of stations (meaning the placement of the compass directions of the principal deities). If one thoroughly understands these four methods, one penetrates all methods of emanation (inquire further). The various altars that emanate from this are all based on what is taught in the fundamental teaching. "Sons of the Buddha" addresses them, meaning Vajrapāṇi and the others. Moreover, regarding the four bodhisattvas: Samantabhadra is in the southeast, Mañjuśrī in the southwest, Maitreya in the northwest, and Avalokiteśvara in the northeast; these are their stations. In the earlier listing of the assembly at the arising of the conditions, Ākāśagarbha sometimes replaced Avalokiteśvara, or Sarvadurgatipariśodhana replaced Mañjuśrī; their meanings differ respectively, and it is also permissible to employ them as needed for a particular purpose; here, using Avalokiteśvara is orthodox.