首楞嚴義疏注經 7.58

7.58

"Sitātapatrā" means the "White Parasol," which refers directly to the matrix mind. Because it does not accord with defilement of delusion, it is called "white." Because it covers all phenomena everywhere, it is called a "parasol." The secret divine mantra flows forth from this, and is thus called the "heart of the mantra." Moreover, it is the overarching summary among all mantras; there is not a single Buddha who has not attained right awakening, restrained the māras and outsiders, responded to lands, and turned the great wheel of the Dharma through this mantra.