大毘盧遮那成佛經疏 16.25

16.25

次西方虛空藏菩薩，即是文殊會中西方部主也。作圓壇令明淨鮮白，坐白蓮上，手持刀。若不畫菩薩形者，但置刀，其刀極利如霜。又如是，謂如是堅利也。又堅固，以種子字而圍繞之也。智者以自種子而種子之，即是安本種子也。次列眷屬上首菩薩，即畫彼印形如教，謂皆依教如法作也。

Next, Ākāśagarbha Bodhisattva in the west is the western family lord in the assembly of Mañjuśrī. Make a circular maṇḍala and make it luminous, pure, and bright white; he sits upon a white lotus, holding a sword in hand. If not painting the Bodhisattva's bodily form, simply place a sword, whose blade is exceedingly sharp like frost. 'Moreover, like this' means like this in hardness and sharpness. It is also solid, surrounded by bīja syllables. The wise person seeds it with its own bīja, which means placing its original bīja. Next, array the chief Bodhisattvas of the retinue; that is, paint their seal forms according to the teaching, meaning that all are made according to the teaching and proper rite.