妙法蓮華經玄義 3.85

3.85

佛眼雖未開，已能圓學圓信。如迦陵頻伽鳥，雖在㲉中，音聲已勝諸鳥，即是假名、相似等妙。若開，即是分妙、究竟妙（云云）。

Although the Buddha-eye is not yet opened, they are already able to practice perfectly and believe perfectly. Like the kalaviṅka bird, which even while still in the egg has a voice superior to all other birds, this is the subtlety of nominal designation, the subtlety of semblance, and so forth. If it is opened, it is the subtlety of partial realization and the ultimate subtlety, and so forth.