大般涅槃經義記 4.234

4.234

初問可知。如來答中，先別、後結。別中，約人就喻顯異。「聲聞如乳，緣覺如酪，菩薩如似生、熟二蘇」，地前如生，地上如熟；亦可七地已還如生，八地已上如似熟蘇。「佛如醍醐」。「以是」下結，就菩薩中生、熟兩分應有五階，合故云四。

The first question can be known. In the Tathāgata's answer, he first distinguishes and later concludes. In distinguishing, he clarifies differences according to persons and with reference to metaphors: "Śrāvakas are like milk, pratyekabuddhas are like curd, bodhisattvas are like raw and clarified butter"—those prior to the grounds are like raw butter, and those on the grounds are like clarified butter; alternatively, those on or below the seventh ground are like raw butter, and those on or above the eighth ground are like clarified butter. "A buddha is like ghee." From "For this reason" downward is the conclusion; within the bodhisattva stage, dividing into raw and clarified would make five levels, but by combining them he speaks of four.