大毘盧遮那成佛經疏 10.20

10.20

得大勢亦入此三昧，與觀音同，由是彼眷屬故。髯髯是生義，所以有二重者，上是煩惱障生，次是所知障生，入阿字門即是二生舉體皆不生也。上有點是大空義，謂除二障得大空生也。娑字是真言種子之體，娑是不動義。不動住動之法即有生滅，凡物有生滅者即有住動之相。故經云「動不動法皆是不安之相。」傍加二點同於涅槃，即是堅住義。已離二障同於大空，堅住此位如諸佛住，即是大勢位也。如世人有大官位，多諸財力、威伏多人，名為有勢之人，此勢即是位也。言度二生同於佛生，即是如來之位。得此大位大勢，故名得大勢也。

Mahāsthāmaprāpta also enters this samādhi, the same as Avalokiteśvara, because he belongs to his retinue. Jaṃ jaṃ has the meaning of arising. Why are there two layers? The first is the arising of the affliction hindrance; the second is the arising of the hindrance to the knowable. Entering the syllable A gateway means that the entire essence of both arisings is unborn. The dot above has the meaning of great emptiness, signifying that by removing the two hindrances one attains the arising of great emptiness. The syllable sa is the essence of the mantra bīja; sa has the meaning of immobility. Phenomena that abide in motion without moving entail arising and ceasing; whatever has arising and ceasing possesses the characteristics of abiding and motion. Therefore the sūtra says: 'Phenomena of motion and non-motion are all marks of disquiet.' Adding two dots to the side makes it identical to nirvāṇa, which is the meaning of firm abiding. Having already transcended the two hindrances and become identical to great emptiness, one firmly abides in this state just as the Buddhas abide; this is the state of great power. Just as in the world a person who possesses high official rank, abundant wealth, and overawes many people is called an influential person, this power is the rank. Saying that one transcends the two arisings and is identical to the Buddha's arising means this is the state of the Tathāgata. Attaining this great state and great power, he is therefore named Mahāsthāmaprāpta.