請觀音經疏闡義鈔 3.61

3.61

The sūtra's "one should recite silently" means chanting quietly in a soft voice. Since this dhāraṇī is like this, the preceding and following sections should be understood by analogy. However, the ritual procedures of the various sūtras differ according to capacity: just as the Tejobala Dhāraṇī orders one to chant in a loud voice, this text has one recite silently. Fortunately, by according with the Buddha's words, one corresponds with the holy intent.