法界次第初門 1.265

1.265

As for expounding the four formless attainments after the immeasurable minds: although there are great virtues within the four immeasurable minds, they have not yet avoided the burdensome afflictions of physical form. If practitioners revile form as like a prison, their minds constantly delight in and desire to escape the cage of form; therefore, following the immeasurables, the four formless attainments are elucidated. That they are generally called 'formless' [or 'empty'] means that the substance of these four meditative absorptions has no physical form; hence they are called 'empty'. Each is designated as a 'base' in accordance with the objective sphere realized; the phenomena of the sphere sustain the mind so that it does not scatter; hence they are called 'attainments' [or 'meditative absorptions'].