大般涅槃經集解 14.32

14.32

案僧亮曰：以鳥譬鳥、以聲譬聲，遍取同鳥，不得相比也；分取，可譬佛聲也。

Sengliang states: Using a bird to analogize a bird, and using a sound to analogize a sound—if taken entirely as the same bird, they cannot be compared; if taken partially, it can analogize the Buddha's voice.