首楞嚴義疏注經 6.74

6.74

天能厭樂、龍能怖苦、樂神蕩逸、藥叉勇健，各慕出倫，非聖不拔。

Devas can tire of pleasure, nāgas can dread suffering, music spirits are licentious and unrestrained, and yakṣas are courageous and robust; each yearns to transcend their species, and none but a sage can pull them out.