法界次第初門 3.117

3.117

次八變化而辯四無礙智者，菩薩若能現種種神通變化，則一切見者無不信伏。眾生既起敬信，若欲闡揚大道，必須無礙辯才，故次八種變化以明四無礙智。此四通名無礙智者，菩薩於此四法智慧捷疾，分別了了，通達無滯，故通名無礙智也。

The reason why the four unhindered analytical knowledges are explained following the eight transformations is that when a bodhisattva can manifest various superknowledges and transformations, all who witness them will unfailingly believe and submit. Once sentient beings have generated reverence and faith, if one wishes to elucidate the Great Way, one must possess unhindered eloquence; therefore, following the eight kinds of transformations, the four unhindered knowledges are clarified. That these four are all termed 'unhindered knowledges' is because with respect to these four dharmas, the bodhisattva's wisdom is swift and agile, distinguishes distinctly, and penetrates without obstruction; hence, they are all termed 'unhindered knowledges'.