首楞嚴義疏注經 6.80

6.80

A human body is difficult to obtain, enabling one to see the Buddha and receive transformation. Unlike the attachment to pleasure of devas, or the preponderance of suffering among the rest, they therefore delight in cultivating it. 'Having form' means having the skandha of form, like the auspicious and ominous luminaries below. 'Formless' means lacking the skandha of form, like the empty, dispersed, sunken, and vanished below. 'With thought' means having four skandhas, like ghosts, spirits, essences, and souls below. 'Thoughtless' means lacking four skandhas, namely those whose spiritual essence transforms into earth, wood, metal, and stone below. All the above are non-humans. Thus, diverse classes of form and thought, all wriggling creatures, receive benefit; [the Bodhisattva] necessarily matches their bodies, transforming them on the spur of the moment.