大般涅槃經義記 3.351

3.351

上來教凡，下教二乘。「若有分別三歸依者」舉其所化，小乘眾生唯取別相名分別三。「我當為」下化之歸一，一佛性中義別三歸，故言為化一歸依處無三差別。

The above was teaching ordinary beings; below is teaching the two vehicles. "If there are those who differentiate the three refuges" adduces those who are to be transformed; Hīnayāna sentient beings grasp only distinct marks, which is called differentiating the three. From "I shall for their sake" downward, he transforms them to take refuge in the one: within the single buddha-nature there are conceptually distinct three refuges, and therefore he says that he transforms them for the sake of a single place of refuge without the three distinctions.