瑜伽論記 11.210

11.210

呪詞有二：一、是有義；二者、無義，即舉無義呪詞思惟觀察，類知一切隨言自性皆不可得，由此思性得成於此陀羅尼忍。

Mantra words are of two kinds: first, those having meaning; second, those without meaning. That is, one adduces meaningless mantra words, contemplates and examines them, and analogically understands that all intrinsic natures corresponding to words are unfindable; through the nature of this contemplation, one accomplishes this dhāraṇī-patience.