大乘起信論義記 3.282

3.282

以如來藏等者，明淨德妙有。以過恒沙等煩惱等者，明妄染理無。從無始已下，明妄不入真。若如來藏體有妄法等者，此明縱破，可知。

The phrase "Because [...] the tathāgatagarbha..." clarifies the wondrous existence of pure virtues. The phrase "Because [...] defiled phenomena of affliction exceeding the sands of the Ganges..." clarifies the non-existence in principle of illusory defilement. From "since beginningless [time]" onward, it clarifies that illusion does not enter into truth. The phrase "If the essence of the tathāgatagarbha possessed illusory phenomena..." clarifies the hypothetical refutation, which is understandable.