大毘盧遮那成佛經疏 3.46

3.46

經偈云「行者悲念心，發起令增廣，彼堅住受教，當為擇平地」者，言阿闍梨已得弟子，次明治地支分也。此中行者字，梵本云真言者，以偈中不可六字，故取意刪之。下文頗有此例，不復煩說。謂真言者數數以如是善法發起其心，即令彼意樂漸得增廣。知彼堅住受教不復移轉，方為作漫荼羅。或於瑜伽中見彼根緣已固，然後擇地也。《金剛頂》大本及《蘇悉地》等經廣說地相，然其大意者，今此世界自不如餘淨域怛然平正，但隨下文所說諸勝處中，擇取平正端嚴可造圓壇之處，輒便動作施為無所妨礙，便可充事也。復次今造諸壇何處皆得，如毘盧遮那遍一切處平正心地，方作大悲漫荼羅。但隨所說勝處中，有少分平正可淨治處，便於此中開出萬德漫荼羅。淺深重數，准前廣釋也。

The sūtra verse says: / "The practitioner's mind of compassion / Is aroused and made to expand; / When he firmly abides and receives instruction, / One should select level ground for him": / this says that when the ācārya has gained a disciple, next he explains the branch of preparing the ground. Here, the word "practitioner" in the Sanskrit text is "mantrin" (mantra practitioner); because six characters cannot fit in a verse, it was abbreviated according to the sense. There are quite a few such cases in the text below, which will not be explained repetitively. It means that the mantrin repeatedly arouses his mind with such wholesome dharmas, causing his aspiration to gradually expand. Knowing that he firmly abides, receives instruction, and will no longer waver, only then does he make the maṇḍala for him. Or, in yoga seeing that his capacity and conditions are already firm, only then does he select the ground. The great text of the Vajraśekhara and the Susiddhi and other sūtras extensively explain the characteristics of the ground; however, the general meaning is that this world is naturally not as completely level and upright as other pure realms, but according to the various superior places explained in the text below, selecting a level, upright, and dignified place where a circular altar can be made, one acts and performs without hindrance, and it can serve the purpose. Furthermore, creating altars anywhere is acceptable now; just as Vairocana's universally omnipresent, level ground of the mind only then makes the mahākaruṇā-maṇḍala, so wherever among the explained superior places there is a small portion that is level and can be purified, right therein one opens forth the maṇḍala of ten thousand virtues. The shallow and deep layers are in accordance with the extensive explanation given before.