成唯識論演祕 1.133

1.133

Feeling itself is bliss; joy (prīti), pleasure (sukha), and equanimity (upekṣā) serve as its substance. Because all three have the meaning of harmony and ease, they are collectively termed 'bliss'. If not so, how could it be said to 'pervade the three realms'? When it says 'not merely pleasure among feelings', it means that it is not only the single pleasant feeling among the five feelings that is named feeling-bliss. When it says 'it is the intrinsic nature of bliss', its substance is the mental factor of feeling, which distinguishes it from causal bliss and the like before and after.