大毘盧遮那經供養次第法疏 1.28

1.28

「右膝著地」以下一段，出罪方便真言門。誦真言同前。實相智自無罪，若執有罪，此智能令解無罪，是故言出罪。

The passage from "placing the right knee on the ground" onward is the mantra gate of the upāya of expelling transgressions. Reciting the mantra is the same as before. The wisdom of dharmatā is naturally without transgression; if one clings to the existence of transgression, this wisdom enables one to understand that there is no transgression, and therefore it is called expelling transgressions.