大毘盧遮那成佛經疏 4.3

4.3

偈云「制底火神祠，牛欄河潬中，諸天廟空室，仙人得道處」者，或雖非聖迹及僧所居，但隨於地分有起制底之處，於其四傍便可造作漫荼羅。火神，是淨行梵志火祠之所，尤為清潔，故可立壇。牛欄者，西方聚落牧牛共在一處，去村或十里五里。既積多時，牛屎尿遍地重積，梵俗亦以為淨。雖然，須牛移去，若牧牛見在，亦不中作也。河灘，正翻當云攢流處，謂有兩水或多水於此處會合。此側及中間，頻經泛漲蕩滌，無諸穢惡。天廟，是宗事世天者齋祈之室，亦多清閑。然有諸外道邪見不信，則不應於此處作也。空室，謂世人所造居室，後時捨之而去，以無諸憒雜，故堪作法。仙人得道處，是世間求五通者久所棲止得成就處，必無餘好處，亦可於中造漫荼羅也。復次制底，是建立高勝義，謂此人常能建立白法志不屈撓，雖未現修聖教，當知先世樹福內有善根，故名為塔。又火能樊滅荒穢，謂此人身口意雖未能清昇出離，然內有慧性，好行淨業、有過能改，故名火祠。牛是行義，欄是閑防義，謂此人質性調柔易可馴御，兼於五情嗜欲能自制止不至放逸，故名牛欄。攢流，謂於三乘中其心猶豫，不知定趣何道。阿闍梨亦當以法勸喻言：「此諸方便皆是佛教，但隨汝最欣樂處一向學之。所到會同，不應疑慮也。」若是邪正雜信，則當斷其迷津示其正路。以能兼信故，即是先世曾經法水盪滌其心，亦名河潬也。天祠，謂不求三乘而志願天樂，為欲授受令離三惡，生正見天中，故須攝受，是名天祠。空室，謂此人雖在塵俗，而性好虛寂厭世囂煩，是善根將熟之相。如女人胎漸成就，則欲意自輕，故堪教化。若志求無色天道，亦名空室也。仙人得道處，謂但發心求五通持明仙道，或願長壽成就世間種種悉地，亦可隨彼情機而誘接之也。復次有諸異學，深樂圍陀火祠之法願生梵世，聞佛祕藏中亦有火天真言行法，旨趣甚深故，即從此門而入正法。復有奉事自在、毘紐、那羅延、日月尊等種種世天，若聞佛祕藏中亦有彼等諸天真言行法，乃至毘盧遮那大我之身，即便信受而入正法。或有志願生三界諸天者，聞佛祕藏中具有諸天乘真言行法，能令於無量世生彼天中不復退墮，終成第一義天，由此深心願樂得入正法者。或有宗習世間五通仙法者，聞佛祕藏中具有迦葉、瞿曇大仙等種種真言，能令獲得不思議神通，乃至如毘盧遮那住壽長遠，彼便踴躍志求得入正法。以如是等種種門故，佛說火神諸處皆可造漫荼羅也。

As for the verse saying:
'Caityas, fire-god shrines,
Cowpens, sandbanks in rivers,
Temples of the devas, empty rooms,
And places where ṛṣis attained the path':
Even if it is not a sacred trace or a dwelling of monks, wherever a caitya has been erected within a locality, one may construct a maṇḍala around its four sides. 'Fire-god' refers to a place of fire sacrifice for pure-conduct brāhmaṇas; being especially clean, an altar may be set up there. 'Cowpen': in the villages of the Western regions, cattle are pastured together in one place, five or ten li away from the village. Having accumulated over a long time, cow dung and urine are piled deeply all over the ground, and Indian custom considers it pure. Even so, the cattle must have moved away; if the pastured cattle are present, it is also unsuitable. 'River sandbank'—the correct translation should be 'confluence of streams'—refers to a place where two or more waters merge. Around its banks and in between, it has repeatedly been flooded, washed, and cleansed, free of all defilement. 'Deva temples' are rooms for fasting and prayer by those who venerate worldly gods, and are also mostly quiet and secluded. However, if there are non-Buddhists of wrong views who lack faith, one should not make it in such a place. 'Empty rooms' refers to dwellings built by worldly people and later abandoned; free of turmoil and disturbance, they are suitable for performing the rites. 'Places where ṛṣis attained the path' are sites where worldly seekers of the five supernatural knowledges long resided and attained accomplishment; if there are definitely no other good sites, one may also make a maṇḍala therein. Furthermore, 'caitya' has the meaning of establishing what is lofty and superior, meaning that this person can constantly establish pure dharmas with unflagging resolve; although not visibly practicing the noble teaching at present, one should know that through merits planted in past lives they have wholesome roots within; hence it is called a stūpa. Moreover, fire can burn away overgrowth and defilement, meaning that although this person's body, speech, and mind cannot yet ascend cleanly to transcendence, they possess an inherent nature of wisdom within, are fond of practicing pure deeds, and are able to reform their faults; hence it is called a fire shrine. 'Cow' has the meaning of conduct, and 'pen' has the meaning of restraint and guarding, meaning that this person's disposition is gentle, pliable, and easily tamed, and that they can self-restrain their desires regarding the five sense passions without falling into heedlessness; hence it is called a cowpen. 'Confluence of streams' refers to those whose minds hesitate among the three vehicles, not knowing which path to definitely pursue. The ācārya should also advise and encourage them with the Dharma, saying: 'All these upāyas are the Buddha's teachings; simply study single-mindedly whatever you most delight in. Where they arrive is identical; you should have no doubts or misgivings.' If their faith is mixed with heterodox and orthodox, one should cut off their ford of delusion and show them the correct path. Because they can hold faith in both, they have previously had their minds washed by Dharma-water in past lives; this is also named a river sandbank. 'Deva shrines' refers to those who do not seek the three vehicles but aspire to celestial pleasures: in order to guide them to leave the three evil destinies and be born among devas of right view, one must gather them in; this is named a deva shrine. 'Empty rooms' refers to a person who, although living in worldly dust, naturally loves emptiness and solitude and disdains worldly clamour; this is a sign that their wholesome roots are about to ripen. Just as when a woman's pregnancy gradually matures, her sexual desire naturally wanes, so they are suitable for being taught. If they aspire to the path of the formless heavens, it is also named an empty room. 'Places where ṛṣis attained the path' refers to those who merely resolve to seek the ṛṣi path of the five supernatural knowledges and vidyādhara status, or wish for longevity to accomplish various worldly siddhis; one may also adapt to their inclinations and draw them in. Furthermore, there are heterodox students who deeply delight in the Vedic fire sacrifice methods and vow to be born in the Brahmā world; hearing that the Buddha's secret treasury also contains the mantra practice of the Fire Deva, with its exceedingly profound significance, they enter the true Dharma through this gateway. There are also those who serve Īśvara, Viṣṇu, Nārāyaṇa, the Sun and Moon Honoured Ones, and other worldly devas: hearing that the Buddha's secret treasury also contains mantras and practices of these devas, extending even to the Great Self body of Vairocana, they immediately believe, accept, and enter the true Dharma. Or there are those who aspire to be born among the devas of the three realms: hearing that the Buddha's secret treasury is replete with mantra practices of the deva vehicles, capable of causing one to be born in those heavens for boundless lifetimes without retrogressing or falling, ultimately attaining the supreme Heaven of Paramount Truth, they enter the true Dharma through this deep mental aspiration. Or there are those who venerate and practice worldly ṛṣi methods of the five supernatural knowledges: hearing that the Buddha's secret treasury is replete with various mantras of the great ṛṣis Kāśyapa, Gautama, and so forth, capable of bringing about inconceivable supernatural powers and even long life like Vairocana's, they leap with joy, make their resolution, and are able to enter the true Dharma. Through such various gateways, the Buddha taught that fire-god shrines and other places are all suitable for constructing a maṇḍala.