大方廣圓覺修多羅了義經略疏 2.65

2.65

These are the retributions of the three evil destinies. The omission of animals is done to embellish the prose into phrasing, using the two to illustrate the third. Or perhaps there was an omission in translation or transcription, for the meaning must include them. Therefore, the Huayan [Sūtra] says: 'The paths of the ten non-virtuous actions: the superior cause rebirth in hell, the middling cause rebirth as animals, and the inferior cause rebirth as hungry ghosts.'