大毘盧遮那成佛經疏 10.144

10.144

上囉是垢，下嚩是縛也。毘是言語道斷，又有三昧也。睇是授與義。伊聲是三昧也。猶自足故則與人。猶自得一切智智故，能以此願與人也。當此是諸佛之心。帝也（二合）此字為種子。與上句阿聲相連，正以此阿聲為種子體也，即本不生義也。

Above, ra is defilement; below, va is bondage. Vi means the cessation of the path of words, and also samādhi. Dhi means imparting. The i sound is samādhi. Because one is self-sufficient, one imparts to others. Because one has personally attained sarvajñajñāna, one can impart this vow to others. Consider this to be the mind of all buddhas. The syllable tya (conjunct) is the bīja. It is connected with the a sound in the preceding phrase, and takes precisely this a sound as the substance of the bīja, which is the meaning of "originally unborn."